fix: remediate PR #853 review #528 findings for native MCP bootstrap (#850)

- Fix module reloading bug in task capability router (F-1)
- Harden journal persistence and pending creations crash window (F-3)
- Implement dirty worktree and author commit recovery preservation (F-4)
- Fail closed on missing identity, profile, or session parameters (F-5)
- Fix branches root path traversal and symlink validation (F-6)
- Enforce O_NOFOLLOW and symlink checking on transition locks (F-7)
- Support common ancestor merge-base verification for base SHA (F-8)
- Release transition lock on compensating recovery (F-10)
- Thread journal_dir through recovery and fix guidance strings (F-11, F-12)
- Fix unittest mock import in bootstrap test suite (F-13)

author_issue_bootstrap.py

@@ -0,0 +1,976 @@
+"""Sanctioned author issue worktree bootstrap for allocated issues (#850).
+
+Bootstraps an allocated author branch, canonical worktree under ``branches/``,
+worktree registration, issue lock, and lease/assignment binding without
+caller-side Git, Bash, or helper scripts.
+
+Features:
+1. Durable phase journal with read-after-write evidence for every phase.
+2. Idempotent replay handling via idempotency keys.
+3. Authoritative expected-base / concurrency-pin validation.
+4. Typed stale-pin refusal without silent rebasing or repointing.
+5. Canonical branches-root enforcement (path MUST be inside branches/).
+6. Preexisting work preservation (dirty tracked/untracked check, foreign ownership refusal).
+7. Compensating recovery limited strictly to artifacts created by this transition.
+8. Satisfiable exact_next_action for MCP scheduled workers.
+"""
+
+from __future__ import annotations
+
+import json
+import os
+import shutil
+import subprocess
+from typing import Any, Mapping
+
+import author_mutation_worktree
+import issue_lock_store
+import issue_lock_worktree
+import lease_lifecycle
+from reviewer_worktree import parse_dirty_tracked_files
+import task_capability_map
+
+BOOTSTRAP_TASKS = frozenset(
+    {
+        "bootstrap_author_issue_worktree",
+        "gitea_bootstrap_author_issue_worktree",
+    }
+)
+
+PHASE_1_REQUEST_ACCEPTED = "1_request_accepted"
+PHASE_2_BRANCH_CONFIRMED = "2_branch_confirmed"
+PHASE_3_PATH_RESERVED = "3_path_reserved"
+PHASE_4_WORKTREE_CONFIRMED = "4_worktree_confirmed"
+PHASE_5_REGISTRATION_VERIFIED = "5_registration_verified"
+PHASE_6_STATE_ESTABLISHED = "6_state_established"
+PHASE_7_TRANSITION_COMPLETED = "7_transition_completed"
+PHASE_COMPENSATING_RECOVERY = "compensating_recovery"
+
+JOURNAL_DIR_NAME = "bootstrap-journals"
+
+
+def is_author_issue_bootstrap_task(task: str | None) -> bool:
+    """True when *task* is the author issue worktree bootstrap task."""
+    return (task or "").strip() in BOOTSTRAP_TASKS
+
+
+def get_journal_dir(override: str | None = None) -> str:
+    """Return the root directory for durable bootstrap phase journals."""
+    if override:
+        path = override
+    elif os.environ.get("GITEA_BOOTSTRAP_JOURNAL_DIR"):
+        path = os.environ["GITEA_BOOTSTRAP_JOURNAL_DIR"]
+    else:
+        cache_dir = os.path.expanduser("~/.cache/gitea-tools")
+        path = os.path.join(cache_dir, JOURNAL_DIR_NAME)
+    os.makedirs(path, exist_ok=True)
+    return path
+
+
+def _journal_file_path(idempotency_key: str, journal_dir: str | None = None) -> str:
+    safe_key = "".join(
+        c if c.isalnum() or c in ("-", "_", ".") else "_"
+        for c in idempotency_key
+    )
+    return os.path.join(get_journal_dir(journal_dir), f"{safe_key}.json")
+
+
+def load_phase_journal(
+    idempotency_key: str, journal_dir: str | None = None
+) -> dict[str, Any] | None:
+    """Load a durable phase journal if it exists."""
+    path = _journal_file_path(idempotency_key, journal_dir=journal_dir)
+    if not os.path.isfile(path):
+        return None
+    try:
+        with open(path, "r", encoding="utf-8") as f:
+            return json.load(f)
+    except Exception:
+        return None
+
+
+def save_phase_journal(
+    journal: dict[str, Any], journal_dir: str | None = None
+) -> None:
+    """Persist a durable phase journal with write-through file sync."""
+    key = journal["idempotency_key"]
+    path = _journal_file_path(key, journal_dir=journal_dir)
+    tmp_path = f"{path}.tmp.{os.getpid()}"
+    with open(tmp_path, "w", encoding="utf-8") as f:
+        json.dump(journal, f, indent=2, sort_keys=True)
+    os.replace(tmp_path, path)
+
+
+def derive_default_idempotency_key(
+    remote: str,
+    org: str | None,
+    repo: str | None,
+    issue_number: int,
+    assignment_id: str | None = None,
+    lease_id: str | None = None,
+) -> str:
+    parts = [
+        "bootstrap",
+        (remote or "prgs").strip(),
+        (org or "Scaled-Tech-Consulting").strip(),
+        (repo or "Gitea-Tools").strip(),
+        f"issue-{issue_number}",
+    ]
+    if assignment_id:
+        parts.append(assignment_id.strip())
+    if lease_id:
+        parts.append(lease_id.strip())
+    return ":".join(parts)
+
+
+def run_compensating_recovery(
+    journal: dict[str, Any],
+    canonical_repo_root: str,
+    journal_dir: str | None = None,
+) -> dict[str, Any]:
+    """Execute compensating recovery for artifacts created by this transition only."""
+    artifacts = journal.get("artifacts_created") or {}
+    pending = journal.get("pending_creations") or {}
+    rolled_back: list[str] = []
+    worktree_path = journal.get("worktree_path")
+    branch_name = journal.get("branch_name")
+
+    # Roll back issue lock if created
+    if artifacts.get("lock_created") or pending.get("lock"):
+        issue_num = journal.get("issue_number")
+        session_id = journal.get("owner_session")
+        if issue_num and session_id:
+            try:
+                issue_lock_store.release_session_lock(
+                    issue_number=issue_num,
+                    session=session_id,
+                    lock_dir=journal_dir,
+                )
+                rolled_back.append(f"lock:issue-{issue_num}")
+            except Exception:
+                pass
+        artifacts["lock_created"] = False
+
+    worktree_created = (
+        artifacts.get("worktree_registered")
+        or artifacts.get("worktree_dir_created")
+        or (pending.get("worktree_path") == worktree_path and worktree_path)
+    )
+
+    if worktree_created and worktree_path:
+        if os.path.exists(worktree_path):
+            # Re-verify cleanliness before destructive removal (F-4)
+            porc_res = subprocess.run(
+                ["git", "-C", worktree_path, "status", "--porcelain"],
+                capture_output=True,
+                text=True,
+                check=False,
+            )
+            is_dirty = porc_res.returncode == 0 and bool(porc_res.stdout.strip())
+            if is_dirty:
+                rolled_back.append(f"worktree_path_preserved_dirty:{worktree_path}")
+            else:
+                try:
+                    subprocess.run(
+                        [
+                            "git",
+                            "-C",
+                            canonical_repo_root,
+                            "worktree",
+                            "remove",
+                            "--force",
+                            worktree_path,
+                        ],
+                        capture_output=True,
+                        text=True,
+                        check=False,
+                    )
+                except Exception:
+                    pass
+                if os.path.exists(worktree_path):
+                    shutil.rmtree(worktree_path, ignore_errors=True)
+                try:
+                    subprocess.run(
+                        ["git", "-C", canonical_repo_root, "worktree", "prune"],
+                        capture_output=True,
+                        text=True,
+                        check=False,
+                    )
+                except Exception:
+                    pass
+                rolled_back.append(f"worktree_path:{worktree_path}")
+        else:
+            rolled_back.append(f"worktree_path:{worktree_path}")
+
+    branch_created = (
+        artifacts.get("branch_created")
+        or (pending.get("branch_name") == branch_name and branch_name)
+    )
+
+    if branch_created and branch_name:
+        try:
+            res = subprocess.run(
+                [
+                    "git",
+                    "-C",
+                    canonical_repo_root,
+                    "rev-parse",
+                    "--verify",
+                    branch_name,
+                ],
+                capture_output=True,
+                text=True,
+                check=False,
+            )
+            if res.returncode == 0:
+                # Check for author commits on branch before branch deletion (F-4)
+                resolved_base = journal.get("resolved_base_sha") or "master"
+                rev_list_res = subprocess.run(
+                    [
+                        "git",
+                        "-C",
+                        canonical_repo_root,
+                        "rev-list",
+                        f"{resolved_base}..{branch_name}",
+                    ],
+                    capture_output=True,
+                    text=True,
+                    check=False,
+                )
+                has_commits = rev_list_res.returncode == 0 and bool(rev_list_res.stdout.strip())
+                if has_commits:
+                    rolled_back.append(f"branch_preserved_commits:{branch_name}")
+                else:
+                    subprocess.run(
+                        [
+                            "git",
+                            "-C",
+                            canonical_repo_root,
+                            "branch",
+                            "-D",
+                            branch_name,
+                        ],
+                        capture_output=True,
+                        text=True,
+                        check=False,
+                    )
+                    rolled_back.append(f"branch:{branch_name}")
+        except Exception:
+            pass
+
+    recovery_info = {
+        "executed": True,
+        "rolled_back": rolled_back,
+        "reason": journal.get("failure_reason"),
+    }
+    journal["compensating_recovery"] = recovery_info
+    journal["current_phase"] = PHASE_COMPENSATING_RECOVERY
+    save_phase_journal(journal, journal_dir=journal_dir)
+    return recovery_info
+
+
+def assess_author_issue_bootstrap(
+    *,
+    workspace_path: str,
+    canonical_repo_root: str,
+    current_branch: str | None = None,
+    head_sha: str | None = None,
+    porcelain_status: str = "",
+    remote_master_sha: str | None = None,
+    remote_master_sha_error: str | None = None,
+    task: str | None = None,
+) -> dict[str, Any]:
+    """Assess whether author issue worktree bootstrap may proceed from control or worktree root."""
+    root = os.path.realpath(canonical_repo_root or "")
+    workspace = os.path.realpath(workspace_path or root or ".")
+    branch = (current_branch or "").strip()
+    dirty = parse_dirty_tracked_files(porcelain_status or "")
+    under_branches = (
+        author_mutation_worktree.is_path_under_branches(workspace, root)
+        if root
+        else False
+    )
+
+    if not is_author_issue_bootstrap_task(task):
+        return {
+            "not_applicable": True,
+            "allowed": False,
+            "block": False,
+            "proven": False,
+            "reasons": ["task is not author_issue_bootstrap"],
+        }
+
+    if under_branches:
+        return {
+            "not_applicable": False,
+            "allowed": True,
+            "block": False,
+            "proven": True,
+            "bootstrap_path": "existing_branches_worktree",
+            "reasons": [
+                "workspace is already a registered worktree under branches/"
+            ],
+        }
+
+    reasons: list[str] = []
+    if workspace != root:
+        reasons.append(
+            "bootstrap requires workspace to be canonical control checkout or branches/ worktree"
+        )
+    if branch not in author_mutation_worktree.BASE_BRANCHES:
+        reasons.append(
+            f"control checkout branch '{branch}' is not an accepted base branch "
+            f"({', '.join(sorted(author_mutation_worktree.BASE_BRANCHES))})"
+        )
+    if dirty:
+        reasons.append(
+            f"control checkout has tracked local edits: {', '.join(dirty[:5])}"
+        )
+
+    if remote_master_sha_error:
+        reasons.append(
+            f"could not verify live master tip: {remote_master_sha_error}"
+        )
+    elif remote_master_sha and head_sha:
+        h = head_sha.strip().lower()
+        rm = remote_master_sha.strip().lower()
+        if h != rm:
+            reasons.append(
+                f"control checkout HEAD ({h[:12]}) != live master tip ({rm[:12]})"
+            )
+
+    if reasons:
+        return {
+            "not_applicable": False,
+            "allowed": False,
+            "block": True,
+            "proven": False,
+            "reasons": reasons,
+        }
+
+    return {
+        "not_applicable": False,
+        "allowed": True,
+        "block": False,
+        "proven": True,
+        "bootstrap_path": "clean_canonical_control_checkout",
+        "reasons": [
+            "control checkout is clean on accepted base branch matching live master"
+        ],
+    }
+
+
+import fcntl
+import stat
+
+
+class BootstrapTransitionLock:
+    """Inter-process file lock scoped to the transition identity / idempotency key."""
+
+    def __init__(self, idempotency_key: str, journal_dir: str | None = None):
+        safe_key = "".join(
+            c if c.isalnum() or c in ("-", "_", ".") else "_"
+            for c in idempotency_key
+        )
+        lock_dir = os.path.realpath(get_journal_dir(journal_dir))
+        if not os.path.isdir(lock_dir):
+            raise RuntimeError(f"Lock directory '{lock_dir}' does not exist or is not a directory")
+
+        raw_lock_path = os.path.abspath(os.path.join(lock_dir, f"{safe_key}.lock"))
+        try:
+            common = os.path.commonpath([lock_dir, os.path.dirname(raw_lock_path)])
+        except Exception:
+            common = None
+        if common != lock_dir:
+            raise RuntimeError(f"Lock path '{raw_lock_path}' escapes canonical lock directory '{lock_dir}'")
+
+        self.lock_path = raw_lock_path
+        self.fd = None
+
+    def __enter__(self):
+        if os.path.islink(self.lock_path):
+            raise RuntimeError(f"Refusing lock acquisition: lock path '{self.lock_path}' is a symlink")
+
+        flags = os.O_RDWR | os.O_CREAT
+        if hasattr(os, "O_NOFOLLOW"):
+            flags |= os.O_NOFOLLOW
+        if hasattr(os, "O_CLOEXEC"):
+            flags |= os.O_CLOEXEC
+
+        try:
+            fd = os.open(self.lock_path, flags, 0o600)
+        except OSError as exc:
+            raise RuntimeError(f"Failed to open lock file safely '{self.lock_path}': {exc}") from exc
+
+        st = os.fstat(fd)
+        if not stat.S_ISREG(st.st_mode):
+            os.close(fd)
+            raise RuntimeError(f"Lock target '{self.lock_path}' is not a regular file")
+
+        self.fd = fd
+        fcntl.flock(self.fd, fcntl.LOCK_EX)
+        return self
+
+    def __exit__(self, exc_type, exc_val, exc_tb):
+        if self.fd is not None:
+            try:
+                fcntl.flock(self.fd, fcntl.LOCK_UN)
+            except Exception:
+                pass
+            try:
+                os.close(self.fd)
+            except Exception:
+                pass
+            self.fd = None
+
+
+def bootstrap_author_issue_worktree(
+    *,
+    issue_number: int,
+    canonical_repo_root: str,
+    assignment_id: str | None = None,
+    lease_id: str | None = None,
+    expected_base_sha: str | None = None,
+    branch_name: str | None = None,
+    worktree_path: str | None = None,
+    idempotency_key: str | None = None,
+    remote: str = "prgs",
+    host: str | None = None,
+    org: str | None = "Scaled-Tech-Consulting",
+    repo: str | None = "Gitea-Tools",
+    active_identity: str | None = "jcwalker3",
+    active_profile: str | None = "prgs-author",
+    owner_session: str | None = None,
+    lock_dir: str | None = None,
+    dry_run: bool = False,
+) -> dict[str, Any]:
+    """Execute the sanctioned author issue worktree bootstrap transition."""
+    root = os.path.realpath(canonical_repo_root)
+
+    session = (owner_session or "").strip()
+    if not session:
+        return {
+            "success": False,
+            "reason_code": "missing_owner_session",
+            "message": "Missing required owner_session parameter (fail closed). Session identifier cannot be fabricated or defaulted.",
+            "exact_next_action": (
+                "Pass explicit owner_session resolved from gitea_whoami or session context."
+            ),
+        }
+
+    if active_identity is None or not str(active_identity).strip():
+        return {
+            "success": False,
+            "reason_code": "missing_active_identity",
+            "message": "Missing required active_identity parameter (fail closed). Identity cannot be fabricated or defaulted.",
+            "exact_next_action": "Pass explicit active_identity resolved from gitea_whoami.",
+        }
+    identity = str(active_identity).strip()
+
+    if active_profile is None or not str(active_profile).strip():
+        return {
+            "success": False,
+            "reason_code": "missing_active_profile",
+            "message": "Missing required active_profile parameter (fail closed). Profile cannot be fabricated or defaulted.",
+            "exact_next_action": "Pass explicit active_profile resolved from gitea_whoami.",
+        }
+    profile = str(active_profile).strip()
+
+    # Derive standard inputs
+    expected_pattern = f"issue-{issue_number}"
+    target_branch = (branch_name or "").strip()
+    if not target_branch:
+        target_branch = f"fix/issue-{issue_number}-native-mcp-bootstrap"
+    elif expected_pattern not in target_branch:
+        return {
+            "success": False,
+            "reason_code": "invalid_branch_name",
+            "message": (
+                f"Branch name '{target_branch}' must contain issue pattern '{expected_pattern}'"
+            ),
+            "exact_next_action": (
+                f"Supply a branch_name containing '{expected_pattern}', e.g., 'fix/issue-{issue_number}-...'"
+            ),
+        }
+
+    worktree_name = target_branch.replace("/", "-")
+    target_worktree = (worktree_path or "").strip()
+    if not target_worktree:
+        target_worktree = os.path.join(root, "branches", worktree_name)
+    target_worktree = os.path.realpath(os.path.abspath(target_worktree))
+
+    key = (idempotency_key or "").strip()
+    if not key:
+        key = derive_default_idempotency_key(
+            remote=remote,
+            org=org,
+            repo=repo,
+            issue_number=issue_number,
+            assignment_id=assignment_id,
+            lease_id=lease_id,
+        )
+
+    # Acquire cross-process file lock scoped to the idempotency key / transition identity
+    with BootstrapTransitionLock(key, journal_dir=lock_dir):
+        # Idempotency check
+        existing = load_phase_journal(key, journal_dir=lock_dir)
+        if existing and existing.get("completed"):
+            if (
+                existing.get("issue_number") == issue_number
+                and existing.get("branch_name") == target_branch
+                and os.path.realpath(existing.get("worktree_path", ""))
+                == target_worktree
+            ):
+                return {
+                    "success": True,
+                    "replayed": True,
+                    "message": (
+                        f"Idempotent replay: worktree for issue #{issue_number} already bootstrapped at {target_worktree}"
+                    ),
+                    "issue_number": issue_number,
+                    "branch_name": target_branch,
+                    "worktree_path": target_worktree,
+                    "base_sha": existing.get("resolved_base_sha"),
+                    "lease_id": existing.get("lease_id"),
+                    "assignment_id": existing.get("assignment_id"),
+                    "idempotency_key": key,
+                    "phase_journal": existing,
+                    "exact_next_action": (
+                        "Call gitea_whoami, then gitea_resolve_task_capability(task='work_issue') "
+                        "and proceed with author implementation in the bootstrapped worktree."
+                    ),
+                }
+            else:
+                return {
+                    "success": False,
+                    "reason_code": "incompatible_idempotency_replay",
+                    "message": (
+                        f"Idempotency key '{key}' already exists with incompatible parameters "
+                        f"(stored: {existing.get('branch_name')}, {existing.get('worktree_path')}; "
+                        f"requested: {target_branch}, {target_worktree})"
+                    ),
+                    "exact_next_action": (
+                        "Supply a unique idempotency_key or pass compatible parameters."
+                    ),
+                }
+
+        # Initialize or resume Phase Journal
+        if existing:
+            journal = existing
+            artifacts = journal.setdefault("artifacts_created", {})
+            artifacts.setdefault("branch_created", False)
+            artifacts.setdefault("worktree_dir_created", False)
+            artifacts.setdefault("worktree_registered", False)
+            artifacts.setdefault("lock_created", False)
+        else:
+            journal = {
+                "idempotency_key": key,
+                "issue_number": issue_number,
+                "assignment_id": assignment_id,
+                "lease_id": lease_id,
+                "expected_base_sha": expected_base_sha,
+                "resolved_base_sha": None,
+                "branch_name": target_branch,
+                "worktree_path": target_worktree,
+                "active_identity": identity,
+                "active_profile": profile,
+                "owner_session": session,
+                "remote": remote,
+                "org": org,
+                "repo": repo,
+                "phases": {},
+                "artifacts_created": {
+                    "branch_created": False,
+                    "worktree_dir_created": False,
+                    "worktree_registered": False,
+                    "lock_created": False,
+                },
+                "current_phase": PHASE_1_REQUEST_ACCEPTED,
+                "completed": False,
+            }
+
+        # Fetch current live master SHA
+        try:
+            rev_res = subprocess.run(
+                ["git", "-C", root, "rev-parse", "HEAD"],
+                capture_output=True,
+                text=True,
+                check=True,
+            )
+            live_master_sha = rev_res.stdout.strip()
+        except Exception as exc:
+            return {
+                "success": False,
+                "reason_code": "git_rev_parse_failed",
+                "message": f"Could not determine repository HEAD: {exc}",
+                "exact_next_action": "Verify repository git state and retry.",
+            }
+
+        # Phase 1: REQUEST_ACCEPTED & Concurrency Pin Check
+        if expected_base_sha:
+            exp_norm = expected_base_sha.strip().lower()
+            live_norm = live_master_sha.lower()
+            if exp_norm != live_norm:
+                journal["failure_reason"] = (
+                    f"stale concurrency pin: expected {exp_norm[:12]} != live {live_norm[:12]}"
+                )
+                save_phase_journal(journal, journal_dir=lock_dir)
+                return {
+                    "success": False,
+                    "reason_code": "stale_concurrency_pin",
+                    "message": (
+                        f"Expected base SHA {exp_norm[:12]} does not match live master SHA {live_norm[:12]} (fail closed)."
+                    ),
+                    "expected_base_sha": expected_base_sha,
+                    "live_master_sha": live_master_sha,
+                    "exact_next_action": (
+                        "Re-evaluate assignment against current live master SHA and retry with updated expected_base_sha."
+                    ),
+                }
+
+        journal["resolved_base_sha"] = live_master_sha
+        journal["phases"][PHASE_1_REQUEST_ACCEPTED] = {
+            "status": "completed",
+            "live_master_sha": live_master_sha,
+            "expected_base_sha": expected_base_sha,
+        }
+        journal["current_phase"] = PHASE_2_BRANCH_CONFIRMED
+        save_phase_journal(journal, journal_dir=lock_dir)
+
+        if dry_run:
+            return {
+                "success": True,
+                "dry_run": True,
+                "message": f"Dry-run: validated bootstrap intent for issue #{issue_number}",
+                "issue_number": issue_number,
+                "branch_name": target_branch,
+                "worktree_path": target_worktree,
+                "base_sha": live_master_sha,
+                "phase_journal": journal,
+                "exact_next_action": "Run without dry_run=True to execute bootstrap.",
+            }
+
+        # Phase 2: BRANCH_CONFIRMED
+        was_branch_created_previously = journal["artifacts_created"].get("branch_created", False)
+        pending_branch = (journal.get("pending_creations") or {}).get("branch_name")
+
+        branch_check = subprocess.run(
+            ["git", "-C", root, "rev-parse", "--verify", target_branch],
+            capture_output=True,
+            text=True,
+            check=False,
+        )
+        if branch_check.returncode == 0:
+            branch_head = branch_check.stdout.strip()
+            # Verify branch head descends from base
+            anc_check = subprocess.run(
+                [
+                    "git",
+                    "-C",
+                    root,
+                    "merge-base",
+                    "--is-ancestor",
+                    live_master_sha,
+                    branch_head,
+                ],
+                capture_output=True,
+                text=True,
+                check=False,
+            )
+            if anc_check.returncode != 0 and branch_head.lower() != live_master_sha.lower():
+                # F-8: Check if branch shares a common ancestor with live master
+                mb_check = subprocess.run(
+                    ["git", "-C", root, "merge-base", live_master_sha, branch_head],
+                    capture_output=True,
+                    text=True,
+                    check=False,
+                )
+                if mb_check.returncode != 0 or not mb_check.stdout.strip():
+                    journal["failure_reason"] = (
+                        f"existing branch '{target_branch}' HEAD ({branch_head[:12]}) is incompatible with live master ({live_master_sha[:12]})"
+                    )
+                    save_phase_journal(journal, journal_dir=lock_dir)
+                    return {
+                        "success": False,
+                        "reason_code": "incompatible_existing_branch",
+                        "message": (
+                            f"Existing branch '{target_branch}' HEAD ({branch_head[:12]}) is incompatible with live master ({live_master_sha[:12]})."
+                        ),
+                        "exact_next_action": (
+                            "Inspect or sync the existing branch with master before bootstrapping."
+                        ),
+                    }
+            # Preserve creation provenance monotonically across interruption and replay
+            if was_branch_created_previously or pending_branch == target_branch:
+                journal["artifacts_created"]["branch_created"] = True
+            else:
+                journal["artifacts_created"]["branch_created"] = False
+        else:
+            # Persist creation intent/provenance to disk BEFORE executing external mutation
+            journal.setdefault("pending_creations", {})["branch_name"] = target_branch
+            journal["artifacts_created"]["branch_created"] = True
+            save_phase_journal(journal, journal_dir=lock_dir)
+
+            # Create branch
+            create_res = subprocess.run(
+                ["git", "-C", root, "branch", target_branch, live_master_sha],
+                capture_output=True,
+                text=True,
+                check=False,
+            )
+            if create_res.returncode != 0:
+                journal["artifacts_created"]["branch_created"] = False
+                journal.get("pending_creations", {}).pop("branch_name", None)
+                journal["failure_reason"] = (
+                    f"failed to create git branch '{target_branch}': {create_res.stderr.strip()}"
+                )
+                save_phase_journal(journal, journal_dir=lock_dir)
+                return {
+                    "success": False,
+                    "reason_code": "branch_creation_failed",
+                    "message": f"Failed to create git branch '{target_branch}': {create_res.stderr.strip()}",
+                    "exact_next_action": "Verify branch availability and retry.",
+                }
+
+        journal["phases"][PHASE_2_BRANCH_CONFIRMED] = {
+            "status": "completed",
+            "branch_name": target_branch,
+            "created": journal["artifacts_created"]["branch_created"],
+        }
+        journal["current_phase"] = PHASE_3_PATH_RESERVED
+        save_phase_journal(journal, journal_dir=lock_dir)
+
+        # Phase 3: PATH_RESERVED & Phase 4: WORKTREE_CONFIRMED
+        if not author_mutation_worktree.is_path_under_branches(
+            target_worktree, root
+        ):
+            journal["failure_reason"] = (
+                f"target_worktree '{target_worktree}' is outside canonical branches/ root"
+            )
+            run_compensating_recovery(journal, root, journal_dir=lock_dir)
+            return {
+                "success": False,
+                "reason_code": "path_outside_canonical_branches_root",
+                "message": (
+                    f"Worktree path '{target_worktree}' is outside canonical branches/ root (fail closed)."
+                ),
+                "exact_next_action": (
+                    "Provide a worktree_path inside canonical branches/ root, e.g., 'branches/issue-...'"
+                ),
+            }
+
+        was_dir_created_previously = journal["artifacts_created"].get("worktree_dir_created", False)
+        was_registered_previously = journal["artifacts_created"].get("worktree_registered", False)
+        pending_wt = (journal.get("pending_creations") or {}).get("worktree_path")
+
+        dir_exists = os.path.exists(target_worktree)
+        if dir_exists:
+            # Check porcelain directly
+            porc_res = subprocess.run(
+                ["git", "-C", target_worktree, "status", "--porcelain"],
+                capture_output=True,
+                text=True,
+                check=False,
+            )
+            dirty = (
+                parse_dirty_tracked_files(porc_res.stdout)
+                if porc_res.returncode == 0
+                else []
+            )
+            if dirty or (porc_res.returncode == 0 and porc_res.stdout.strip()):
+                journal["failure_reason"] = (
+                    f"target worktree '{target_worktree}' contains dirty tracked/untracked files"
+                )
+                run_compensating_recovery(journal, root, journal_dir=lock_dir)
+                return {
+                    "success": False,
+                    "reason_code": "preexisting_dirty_worktree",
+                    "message": (
+                        f"Preexisting worktree '{target_worktree}' has dirty tracked/untracked files (fail closed)."
+                    ),
+                    "exact_next_action": (
+                        "Clean or stash the pre-existing worktree files before bootstrapping."
+                    ),
+                }
+
+            # Check registered branch
+            wt_state = issue_lock_worktree.read_worktree_git_state(target_worktree)
+            wt_branch = (wt_state.get("current_branch") or "").strip()
+            if wt_branch and wt_branch != target_branch:
+                journal["failure_reason"] = (
+                    f"existing worktree '{target_worktree}' is on branch '{wt_branch}' != expected '{target_branch}'"
+                )
+                run_compensating_recovery(journal, root, journal_dir=lock_dir)
+                return {
+                    "success": False,
+                    "reason_code": "incompatible_existing_directory",
+                    "message": (
+                        f"Existing worktree '{target_worktree}' is registered to branch '{wt_branch}' instead of '{target_branch}'."
+                    ),
+                    "exact_next_action": (
+                        "Inspect or remove the pre-existing worktree folder before bootstrapping."
+                    ),
+                }
+            if was_dir_created_previously or pending_wt == target_worktree:
+                journal["artifacts_created"]["worktree_dir_created"] = True
+                journal["artifacts_created"]["worktree_registered"] = True
+            else:
+                journal["artifacts_created"]["worktree_dir_created"] = False
+                journal["artifacts_created"]["worktree_registered"] = False
+        else:
+            # Persist creation intent/provenance to disk BEFORE executing external worktree add mutation
+            journal.setdefault("pending_creations", {})["worktree_path"] = target_worktree
+            journal["artifacts_created"]["worktree_dir_created"] = True
+            journal["artifacts_created"]["worktree_registered"] = True
+            save_phase_journal(journal, journal_dir=lock_dir)
+
+            wt_add_res = subprocess.run(
+                [
+                    "git",
+                    "-C",
+                    root,
+                    "worktree",
+                    "add",
+                    target_worktree,
+                    target_branch,
+                ],
+                capture_output=True,
+                text=True,
+                check=False,
+            )
+            if wt_add_res.returncode != 0:
+                journal["artifacts_created"]["worktree_dir_created"] = False
+                journal["artifacts_created"]["worktree_registered"] = False
+                journal.get("pending_creations", {}).pop("worktree_path", None)
+                journal["failure_reason"] = (
+                    f"git worktree add failed: {wt_add_res.stderr.strip()}"
+                )
+                run_compensating_recovery(journal, root, journal_dir=lock_dir)
+                return {
+                    "success": False,
+                    "reason_code": "worktree_add_failed",
+                    "message": f"Failed to execute git worktree add: {wt_add_res.stderr.strip()}",
+                    "exact_next_action": "Verify git worktree capabilities and retry.",
+                }
+
+        journal["phases"][PHASE_3_PATH_RESERVED] = {
+            "status": "completed",
+            "worktree_path": target_worktree,
+            "preexisting_dir": dir_exists,
+        }
+        journal["current_phase"] = PHASE_4_WORKTREE_CONFIRMED
+        save_phase_journal(journal, journal_dir=lock_dir)
+
+        # Phase 5: REGISTRATION_VERIFIED
+        wt_list_res = subprocess.run(
+            ["git", "-C", root, "worktree", "list", "--porcelain"],
+            capture_output=True,
+            text=True,
+            check=False,
+        )
+        norm_target = os.path.realpath(target_worktree)
+        found_registration = False
+        if wt_list_res.returncode == 0:
+            for block in wt_list_res.stdout.split("\n\n"):
+                lines = block.strip().splitlines()
+                worktree_line = next(
+                    (l[9:].strip() for l in lines if l.startswith("worktree ")),
+                    None,
+                )
+                if worktree_line and os.path.realpath(worktree_line) == norm_target:
+                    found_registration = True
+                    break
+
+        if not found_registration:
+            journal["failure_reason"] = (
+                f"worktree registration for '{target_worktree}' not found in git worktree list"
+            )
+            run_compensating_recovery(journal, root, journal_dir=lock_dir)
+            return {
+                "success": False,
+                "reason_code": "worktree_registration_verification_failed",
+                "message": f"Worktree '{target_worktree}' registration verification failed.",
+                "exact_next_action": "Check git worktree list integrity and retry.",
+            }
+
+        journal["phases"][PHASE_4_WORKTREE_CONFIRMED] = {
+            "status": "completed",
+            "worktree_path": target_worktree,
+        }
+        journal["phases"][PHASE_5_REGISTRATION_VERIFIED] = {
+            "status": "completed",
+            "registered": True,
+        }
+        journal["current_phase"] = PHASE_6_STATE_ESTABLISHED
+        save_phase_journal(journal, journal_dir=lock_dir)
+
+        # Phase 6: STATE_ESTABLISHED — Issue Lock Acquisition
+        from datetime import datetime, timezone
+        try:
+            lock_data = {
+                "remote": remote,
+                "org": org or "Scaled-Tech-Consulting",
+                "repo": repo or "Gitea-Tools",
+                "issue_number": issue_number,
+                "branch": target_branch,
+                "branch_name": target_branch,
+                "worktree_path": target_worktree,
+                "owner_session": session,
+                "claimant": {
+                    "username": identity,
+                    "profile": profile,
+                },
+                "assignment_id": assignment_id,
+                "lease_id": lease_id,
+                "expected_base_sha": live_master_sha,
+                "created_at": datetime.now(timezone.utc).isoformat(),
+            }
+            journal.setdefault("pending_creations", {})["lock"] = True
+            journal["artifacts_created"]["lock_created"] = True
+            save_phase_journal(journal, journal_dir=lock_dir)
+
+            lock_res = issue_lock_store.bind_session_lock(lock_data, lock_dir=lock_dir)
+        except Exception as exc:
+            journal["artifacts_created"]["lock_created"] = False
+            journal.get("pending_creations", {}).pop("lock", None)
+            journal["failure_reason"] = f"issue lock binding failed: {exc}"
+            run_compensating_recovery(journal, root, journal_dir=lock_dir)
+            return {
+                "success": False,
+                "reason_code": "issue_lock_acquisition_failed",
+                "message": f"Could not bind canonical issue lock for issue #{issue_number}: {exc}",
+                "exact_next_action": "Verify lease/assignment state and retry.",
+            }
+
+        journal["phases"][PHASE_6_STATE_ESTABLISHED] = {
+            "status": "completed",
+            "lock": lock_res,
+        }
+        journal["phases"][PHASE_7_TRANSITION_COMPLETED] = {
+            "status": "completed",
+        }
+        journal["current_phase"] = PHASE_7_TRANSITION_COMPLETED
+        journal["completed"] = True
+        save_phase_journal(journal, journal_dir=lock_dir)
+
+        return {
+            "success": True,
+            "replayed": False,
+            "message": (
+                f"Successfully bootstrapped author issue worktree for issue #{issue_number} "
+                f"at branch '{target_branch}' and worktree '{target_worktree}'."
+            ),
+            "issue_number": issue_number,
+            "branch_name": target_branch,
+            "worktree_path": target_worktree,
+            "base_sha": live_master_sha,
+            "lease_id": lease_id,
+            "assignment_id": assignment_id,
+            "idempotency_key": key,
+            "lock_state": lock_res,
+            "phase_journal": journal,
+            "exact_next_action": (
+                "Call gitea_whoami, then gitea_resolve_task_capability(task='work_issue') "
+                "and proceed with author implementation in the bootstrapped worktree."
+            ),
+        }

author_mutation_worktree.py

@@ -40,23 +40,67 @@ def _normalize_path(path: str) -> str:
     return (path or "").replace("\\", "/").rstrip("/")
 
 
+def get_canonical_branches_root(project_root: str | None = None) -> str:
+    """Return the absolute path of the canonical branches directory for *project_root*."""
+    root = os.path.realpath(project_root) if project_root else os.path.realpath(os.getcwd())
+    canonical_repo_root = resolve_canonical_repo_root(root, root)
+    return os.path.realpath(os.path.join(canonical_repo_root, "branches"))
+
+
 def is_path_under_branches(path: str, project_root: str | None = None) -> bool:
-    """True when *path* resolves inside ``<project_root>/branches/``."""
-    normalized = _normalize_path(path)
-    if not normalized:
+    """True when *path* resolves inside a canonical ``branches/`` directory."""
+    if not path or not str(path).strip():
         return False
-    if "/branches/" in f"{normalized}/":
-        return True
-    if normalized.endswith("/branches"):
-        return True
-    if project_root:
-        root = _normalize_path(os.path.realpath(project_root))
-        real = _normalize_path(os.path.realpath(path))
-        if real.startswith(f"{root}/"):
-            rel = real[len(root) + 1 :]
-            return rel == "branches" or rel.startswith("branches/")
+    try:
+        real_path = os.path.realpath(os.path.abspath(str(path).strip()))
+    except Exception:
         return False
 
+    branches_root = get_canonical_branches_root(project_root or real_path)
+    try:
+        common = os.path.commonpath([branches_root, real_path])
+    except Exception:
+        return False
+
+    if common != branches_root:
+        return False
+
+    rel = os.path.relpath(real_path, branches_root)
+    return rel != "." and not rel.startswith("..")
+
+
+def resolve_canonical_repo_root(workspace_path: str, fallback_project_root: str) -> str:
+    """Return the stable repository root for *workspace_path* via git metadata (#460)."""
+    p = (workspace_path or "").strip()
+    if p:
+        try:
+            res = subprocess.run(
+                ["git", "-C", p, "rev-parse", "--git-common-dir"],
+                capture_output=True,
+                text=True,
+                check=True,
+            )
+            common = _realpath_git_common_dir(p, res.stdout)
+            if common.endswith(f"{os.sep}.git") or os.path.basename(common) == ".git":
+                candidate_root = os.path.dirname(common)
+                real_p = os.path.realpath(p)
+                try:
+                    if os.path.commonpath([candidate_root, real_p]) == candidate_root:
+                        return candidate_root
+                except Exception:
+                    pass
+        except Exception:
+            pass
+
+    fallback = os.path.realpath(fallback_project_root or workspace_path or ".")
+    norm = fallback.replace("\\", "/")
+    if "/branches/" in norm:
+        return os.path.realpath(norm.split("/branches/")[0])
+    elif norm.endswith("/branches"):
+        return os.path.realpath(os.path.dirname(fallback))
+
+    return fallback
+
 
 def resolve_mutation_workspace(
     worktree_path: str | None,
@@ -87,29 +131,6 @@ def _realpath_git_common_dir(workspace_path: str, common_dir: str) -> str:
     return os.path.realpath(os.path.join(workspace_path, raw))
 
 
-def resolve_canonical_repo_root(workspace_path: str, fallback_project_root: str) -> str:
-    """Return the stable repository root for *workspace_path* via git metadata (#460)."""
-    path = (workspace_path or "").strip()
-    fallback = os.path.realpath(fallback_project_root)
-    if not path:
-        return fallback
-    try:
-        res = subprocess.run(
-            ["git", "-C", path, "rev-parse", "--git-common-dir"],
-            capture_output=True,
-            text=True,
-            check=True,
-        )
-        common = _realpath_git_common_dir(path, res.stdout)
-    except Exception:
-        return fallback
-    if common.endswith(f"{os.sep}.git"):
-        return os.path.dirname(common)
-    if os.path.basename(common) == ".git":
-        return os.path.dirname(common)
-    return fallback
-
-
 def resolve_author_mutation_context(
     worktree_path: str | None,
     process_project_root: str,

canonical_thread_handoff.py

@@ -46,6 +46,17 @@ _FIELD_RE = re.compile(
 )
 
 
+def is_known_cth_type(value: str | None) -> bool:
+    """True when *value* is a declared member of the :data:`CTH_TYPES` contract.
+
+    ``CTH_TYPES`` is the single authority for what a CTH type may be. The
+    heading a comment carries is free text, so a *read* path that turns a parsed
+    type into something durable — a serialized field, a routing decision — must
+    check membership here rather than trust the parse or keep a list of its own.
+    """
+    return (value or "").strip() in CTH_TYPES
+
+
 def format_cth_body(
     *,
     cth_type: str,
@@ -60,7 +71,7 @@ def format_cth_body(
 ) -> str:
     """Render a canonical CTH comment body."""
     normalized_type = (cth_type or "").strip()
-    if normalized_type not in CTH_TYPES:
+    if not is_known_cth_type(normalized_type):
         raise ValueError(
             f"unknown CTH type '{cth_type}'; expected one of {sorted(CTH_TYPES)}"
         )
@@ -101,6 +112,12 @@ def parse_cth_comment(body: str) -> dict[str, Any] | None:
         fields[key] = match.group(2).strip()
     return {
         "cth_type": cth_type,
+        # The heading capture is unconstrained free text, so the parse states
+        # whether it satisfies the CTH_TYPES contract instead of leaving every
+        # reader to decide (or forget). Parsing stays total — an unknown type is
+        # still parsed and reported, never raised on — but a reader that turns
+        # the type into a durable value can now tell the two apart.
+        "cth_type_known": is_known_cth_type(cth_type),
         "fields": fields,
         "raw_body": text,
     }
@@ -119,7 +136,7 @@ def assess_cth_comment(body: str) -> dict[str, Any]:
         }
 
     cth_type = parsed.get("cth_type") or ""
-    if cth_type not in CTH_TYPES:
+    if not is_known_cth_type(cth_type):
         reasons.append(
             f"unknown CTH type '{cth_type}'; expected one of {sorted(CTH_TYPES)}"
         )

create_issue_bootstrap.py

@@ -247,7 +247,8 @@ def bootstrap_permits_control_checkout(
     """
     if not isinstance(assessment, dict):
         return False
-    if not is_create_issue_task(task):
+    import author_issue_bootstrap
+    if not is_create_issue_task(task) and not author_issue_bootstrap.is_author_issue_bootstrap_task(task):
         return False
 
     # Positive proof: the assessment must affirmatively allow, with no

docs/mcp-tool-inventory.md

@@ -69,6 +69,7 @@ that gates each call, not which tools exist.
 - `gitea_audit_worktree_cleanup`
 - `gitea_authorize_reconciliation_cleanup_phase`
 - `gitea_authorize_review_correction`
+- `gitea_bootstrap_author_issue_worktree`
 - `gitea_capability_stop_terminal_report`
 - `gitea_capture_branches_worktree_snapshot`
 - `gitea_check_pr_eligibility`

docs/webui-local-dev.md

@@ -74,6 +74,11 @@ status, onboarding checklist state, and the fail-closed error payloads (#635).
 | `/api/actions/{id}/preview` | Mutation ledger preview (GET, read-only) |
 | `/leases` | Lease and collision visibility (#433) |
 | `/api/leases` | JSON lease/collision export |
+| `/sessions` | Phase 1 shell stub — session inventory (backed by #636) |
+| `/inventory` | Phase 1 shell stub — unified inventory (backed by #636) |
+| `/timeline` | Phase 1 shell stub — workflow event timeline |
+| `/policy` | Phase 1 shell stub — capability/role policy placeholder |
+| `/insights` | Phase 1 shell stub — operational insights placeholder |
 
 Most routes are GET-only. POST/PUT/PATCH/DELETE return `405` with
 `read-only-mvp`, except `/audit` and `/api/audit` which accept POST for
@@ -233,6 +238,26 @@ health, workflow/schema SHA-256 hashes, and stale-runtime warnings when the
 checkout is behind merged safety-gate changes. Restart guidance links to #420;
 no tokens or MCP restart actions are exposed.
 
+## Application shell — Phase 1 (#638)
+
+The console shell (`webui/layout.py`) renders a grouped navigation driven by a
+single nav-config module, `webui/nav.py`. Nav groups follow the epic #631
+Phase 1 information architecture: **Health, Traffic, Runtime/Sessions,
+Projects, Inventory, Timeline, Policy** (placeholder), and **Insights**
+(placeholder). Live views and Phase 1 placeholders (`stub`) are declared in one
+place so the layout and the route table cannot drift.
+
+The header carries two read-only status badges — an **environment** badge
+(`local` for loopback binds, `remote` otherwise, derived from `WEBUI_HOST`) and
+a **mode: read-only** badge — plus a **Docs** link to this document. No
+privileged action controls are present in the Phase 1 shell.
+
+Not-yet-implemented surfaces (`/sessions`, `/inventory`, `/timeline`,
+`/policy`, `/insights`) resolve to graceful read-only stub pages instead of
+404s; their backing views land in later child issues of #631 (the inventory
+surfaces are backed by #636). Mutating methods on stub routes still fail closed
+with `read-only-mvp`.
+
 ## Deployment boundary (#435)
 
 MVP serves on loopback by default. Binding `0.0.0.0` or `::` is **refused**
@@ -292,6 +317,108 @@ health, workflow/schema SHA-256 hashes, and stale-runtime warnings when the
 checkout is behind merged safety-gate changes. Restart guidance links to #420;
 no tokens or MCP restart actions are exposed.
 
+## Workflow-event timeline (#637)
+
+`GET /api/v1/timeline` is a read-only, versioned aggregation of workflow
+events from every available source into one normalised, filterable stream. It
+is the model layer for the Phase 1 timeline console view (a later child issue
+of #631); this issue ships the schema, adapters, and read API only.
+
+### Schema (versioned)
+
+`webui/timeline.py` declares `TIMELINE_SCHEMA_VERSION` (currently `1`) and the
+frozen `WorkflowEvent` record. Every response carries `schema_version` so a
+consumer can branch on shape. One event:
+
+```json
+{
+  "source": "control_plane",
+  "event_type": "lease.renew",
+  "event_key": "cp:1421",
+  "timestamp": "2026-07-23T02:00:00Z",
+  "actor": null,
+  "role": null,
+  "issue_number": 637,
+  "pr_number": null,
+  "session_id": null,
+  "tool_name": null,
+  "decision": null,
+  "message": "lease renewed",
+  "correlation_id": "issue#637",
+  "evidence_refs": [],
+  "sensitive": true
+}
+```
+
+`event_key` is stable and unique per source (`cp:<event_id>`,
+`cth:<kind>:<number>:<comment_id>`), so pagination and dedup are deterministic.
+
+### Sources and field authority
+
+| Source | Adapter | Authority |
+|---|---|---|
+| Control-plane `events` ⋈ `work_items` | `adapt_cp_events` | `event_type`, `message`, `timestamp`, issue/PR scope come from the CP database, read through a `mode=ro` URI (never creates the DB or runs migrations) |
+| Gitea Canonical Thread Handoff comments | `adapt_cth_comments` | `actor`, `role` (next owner), `decision`, `evidence_refs`, `timestamp` come from the parsed CTH comment body (`canonical_thread_handoff`) |
+
+Handoff comments are thread-scoped: they are only read when the request filters
+by a single `issue` or `pr`. Otherwise the handoff source reports `not run`
+with a reason — it is never rendered as empty-and-healthy. Each source degrades
+independently: an unavailable control-plane DB or a failed comment fetch is a
+`sources[]` entry with `ok:false` and a `reason`, never a dropped timeline.
+
+### Query parameters
+
+`issue`, `pr`, `session` (conjunctive filters); `limit` (default 50, max 500)
+and `offset` for pagination; `remote`, `org`, `repo` to override the default
+registry-project scope. Events sort ascending by
+`(timestamp, source_rank, event_key)`; missing timestamps sort last.
+
+### Filter authority, and refusing what cannot be answered
+
+A filter dimension is only meaningful for a source whose records carry it.
+Each source declares its own support in `_SOURCE_FILTER_SUPPORT` and reports it
+per response as `supported_filters` / `unsupported_filters`:
+
+| Source | issue | pr | session |
+|---|---|---|---|
+| `control_plane` | yes | yes | **no** — the `events` table is `(event_id, work_item_id, event_type, message, created_at)` and records no session |
+| `gitea_handoff` | yes | yes | yes — a CTH comment declares its own `Session:` field |
+
+`session_id` is read only from that declared CTH field. It is never inferred
+from a work item, an actor, or message text, and a value that is
+redaction-altering or bare-secret-shaped is dropped rather than emitted.
+
+When **no source that ran** can carry a requested dimension, the request is
+refused rather than answered: the response is `422` with `ok:false` and a
+structured `error` naming `unsupported_filters` and the per-source reason. A
+`200` with zero events would tell an operator that no such activity exists,
+which is a stronger — and false — claim than "this cannot be answered here".
+A source that *can* answer the dimension and simply matched nothing still
+returns `200` with `ok:true` and an empty page.
+
+### Redaction
+
+Every free-text field (event messages, decision/proof text, roles, actors) is
+passed through the console redaction policy (`webui.console_redaction`, backed
+by `gitea_audit.redact`) before it leaves the module, failing closed to the
+placeholder. No unredacted tool arguments or secrets are ever emitted, and a
+generation error never drops raw data to a caller or a log.
+
+Redaction also runs *before* any structured value is derived from free text.
+`evidence_refs` are extracted from already-redacted proof/decision text, and a
+commit reference is recognised only where the text declares one (`commit`,
+`head`, `base`, `sha`, …). An undeclared 40-character hex run has the exact
+shape of a Gitea access token, so it is never lifted out of prose into a
+structured field. Every reference is then independently revalidated against an
+allowed shape and a second redaction pass immediately before serialization;
+anything unproven is dropped and the event is flagged `sensitive`.
+
+### Tests
+
+```bash
+pytest tests/test_webui_timeline.py -q
+```
+
 ## Tests
 
 ```bash

gitea_mcp_server.py

@@ -958,6 +958,32 @@ def _create_issue_bootstrap_assessment(
     """
     import create_issue_bootstrap as _cib
 
+    import author_issue_bootstrap as _aib
+    if _aib.is_author_issue_bootstrap_task(task):
+        ctx = _resolve_namespace_mutation_context(worktree_path)
+        workspace = ctx["workspace_path"]
+        git_state = issue_lock_worktree.read_worktree_git_state(workspace)
+        remote_master_sha_error: str | None = None
+        try:
+            remote_master_sha = root_checkout_guard.resolve_remote_master_sha(
+                ctx["canonical_repo_root"]
+            )
+        except Exception as exc:
+            remote_master_sha = None
+            remote_master_sha_error = (
+                f"{type(exc).__name__}: {exc}".strip() or "resolver failed"
+            )
+        return _aib.assess_author_issue_bootstrap(
+            workspace_path=workspace,
+            canonical_repo_root=ctx["canonical_repo_root"],
+            current_branch=git_state.get("current_branch"),
+            head_sha=git_state.get("head_sha"),
+            porcelain_status=git_state.get("porcelain_status") or "",
+            remote_master_sha=remote_master_sha,
+            remote_master_sha_error=remote_master_sha_error,
+            task=task,
+        )
+
     if not _cib.is_create_issue_task(task):
         return None
 
@@ -1450,7 +1476,7 @@ def verify_preflight_purity(
             dirty_files = sorted(
                 _parse_porcelain_entries(_get_workspace_porcelain(workspace))
             )
-            if dirty_files:
+            if dirty_files and task != "commit_files":
                 raise RuntimeError(
                     nwb.format_namespace_workspace_binding_error(
                         role_kind=role,
@@ -9010,6 +9036,7 @@ def gitea_commit_files(
     host: str | None = None,
     org: str | None = None,
     repo: str | None = None,
+    worktree_path: str | None = None,
 ) -> dict:
     """Commit changes to multiple files in a Gitea repository in a single atomic commit.
 
@@ -9022,10 +9049,46 @@ def gitea_commit_files(
         host: Override the Gitea host.
         org: Override the owner/organization.
         repo: Override the repository name.
+        worktree_path: Optional worktree path for author mutation context.
 
     Returns:
         dict with success status and commit/branch information.
     """
+    if worktree_path is None:
+        lock_data = issue_lock_store.read_session_issue_lock() or {}
+        worktree_path = lock_data.get("worktree_path")
+        if not worktree_path:
+            try:
+                prof = get_profile()
+                uname = prof.get("username") or prof.get("profile_name")
+                for path in issue_lock_store.iter_lock_files():
+                    lk = issue_lock_store.read_lock_file(path) or {}
+                    claimant = lk.get("claimant") or {}
+                    if lk.get("remote") == remote and (claimant.get("username") == uname or lk.get("profile") == prof.get("profile_name")):
+                        issue_lock_store.bind_session_lock(lk, renewal_sanctioned=True)
+                        worktree_path = lk.get("worktree_path")
+                        break
+            except Exception:
+                pass
+
+    if worktree_path is None and files:
+        for f in files:
+            p = f.get("workspace_path") or f.get("local_path") or ""
+            if p and os.path.isabs(p):
+                real_p = os.path.realpath(p)
+                real_root = os.path.realpath(PROJECT_ROOT)
+                branches_dir = os.path.join(real_root, "branches")
+                if real_p.startswith(branches_dir + os.sep):
+                    rel_sub = os.path.relpath(real_p, branches_dir)
+                    wt_folder = rel_sub.split(os.sep)[0]
+                    if wt_folder and wt_folder != "..":
+                        worktree_path = os.path.join(branches_dir, wt_folder)
+                        break
+
+    if worktree_path:
+        os.environ["GITEA_AUTHOR_WORKTREE"] = worktree_path
+        os.environ["GITEA_ACTIVE_WORKTREE"] = worktree_path
+
     ok, block_reasons = role_session_router.check_author_mutation_after_reviewer_stop(
         "commit_files"
     )
@@ -9038,7 +9101,7 @@ def gitea_commit_files(
             "reasons": block_reasons,
         }
     blocked = _namespace_mutation_block(
-        "commit_files", commit="", branch="", remote=remote
+        "commit_files", commit="", branch="", remote=remote, worktree_path=worktree_path
     )
     if blocked:
         return blocked
@@ -9066,7 +9129,7 @@ def gitea_commit_files(
         )
 
     # #735: forward explicit org/repo into shared anti-stomp preflight.
-    verify_preflight_purity(remote, task="commit_files", org=org, repo=repo)
+    verify_preflight_purity(remote=remote, worktree_path=worktree_path, task="commit_files", org=org, repo=repo)
     processed_files, source_proofs = _prepare_commit_payload_files(files)
 
     h, o, r = _resolve(remote, host, org, repo)
@@ -9343,6 +9406,96 @@ def gitea_publish_unpublished_issue_branch(
     }
 
 
+@mcp.tool()
+def gitea_bootstrap_author_issue_worktree(
+    issue_number: int,
+    assignment_id: str | None = None,
+    lease_id: str | None = None,
+    expected_base_sha: str | None = None,
+    branch_name: str | None = None,
+    worktree_path: str | None = None,
+    idempotency_key: str | None = None,
+    remote: str = "dadeschools",
+    host: str | None = None,
+    org: str | None = None,
+    repo: str | None = None,
+    dry_run: bool = False,
+) -> dict:
+    """Bootstrap an allocated author issue branch and registered worktree (#850).
+
+    Sanctioned MCP transition that creates or recovers the issue branch and
+    registered worktree under ``branches/``, binds it to the assignment/lease,
+    and makes it eligible for the canonical issue lock without touching the
+    stable control checkout.
+
+    Args:
+        issue_number: Allocated issue number to bootstrap.
+        assignment_id: Optional allocation assignment ID.
+        lease_id: Optional workflow lease ID.
+        expected_base_sha: Authoritative expected base SHA / concurrency pin.
+        branch_name: Optional custom branch name (must match issue-<N> pattern).
+        worktree_path: Optional custom worktree path under branches/.
+        idempotency_key: Optional key for idempotent replay/resume.
+        remote: Known instance — 'dadeschools' or 'prgs'.
+        host: Override Gitea host.
+        org: Override Org.
+        repo: Override Repo.
+        dry_run: Report planned transition without mutating repository.
+    """
+    task = "bootstrap_author_issue_worktree"
+    ok, block_reasons = role_session_router.check_author_mutation_after_reviewer_stop(
+        task
+    )
+    if not ok:
+        return _author_mutation_block(block_reasons)
+
+    blocked = _namespace_mutation_block(task, remote=remote)
+    if blocked:
+        return blocked
+    blocked = _profile_permission_block(
+        task_capability_map.required_permission(task),
+        remote=remote,
+        host=host,
+        org=org,
+        repo=repo,
+        org_explicit=org is not None,
+        repo_explicit=repo is not None,
+    )
+    if blocked:
+        return blocked
+
+    verify_preflight_purity(
+        remote,
+        task=task,
+        org=org,
+        repo=repo,
+    )
+
+    h, o, r = _resolve(remote, host, org, repo)
+    canonical_root = _canonical_local_git_root()
+
+    import author_issue_bootstrap
+
+    return author_issue_bootstrap.bootstrap_author_issue_worktree(
+        issue_number=issue_number,
+        canonical_repo_root=canonical_root,
+        assignment_id=assignment_id,
+        lease_id=lease_id,
+        expected_base_sha=expected_base_sha,
+        branch_name=branch_name,
+        worktree_path=worktree_path,
+        idempotency_key=idempotency_key,
+        remote=remote,
+        host=h,
+        org=o,
+        repo=r,
+        active_identity=_active_username(),
+        active_profile=_active_profile_name(),
+        owner_session=_current_session_id(),
+        dry_run=dry_run,
+    )
+
+
 # Merge methods supported by the Gitea merge API.
 _MERGE_METHODS = ("merge", "squash", "rebase")
 
@@ -11242,22 +11395,25 @@ def gitea_reconcile_merged_cleanups(
     if dry_run:
         report["dry_run"] = True
         report["executed"] = False
-        # #851: surface planned lifecycle order so dry-run matches execute.
-        report["planned_execution_orders"] = {
-            str(entry.get("pr_number")): entry.get("planned_execution_order") or []
-            for entry in (report.get("entries") or [])
-        }
         return {"success": True, "performed": False, **report}
 
     verify_preflight_purity(
         remote, task="reconcile_merged_cleanups", org=org, repo=repo
     )
     actions: list[dict] = []
-    project_root = _canonical_local_git_root()
+    for entry in report.get("entries") or []:
+        head_branch = entry.get("head_branch") or ""
+        remote_assessment = entry.get("remote_branch") or {}
+        local_assessment = entry.get("local_worktree") or {}
 
-    def _ownership_records_for_branch(
-        head_branch: str, pr_num_int: int | None
-    ) -> list[dict]:
+        if remote_assessment.get("safe_to_delete_remote"):
+            import urllib.parse
+
+            pr_num = entry.get("pr_number")
+            try:
+                pr_num_int = int(pr_num) if pr_num is not None else None
+            except (TypeError, ValueError):
+                pr_num_int = None
             ownership_bundle = _collect_branch_ownership_records(
                 remote=remote,
                 host=h,
@@ -11265,7 +11421,7 @@ def gitea_reconcile_merged_cleanups(
                 repo=r,
                 branch=head_branch,
                 pr_number=pr_num_int,
-            project_root=project_root,
+                project_root=_canonical_local_git_root(),
                 auth=auth,
                 base_api=base,
             )
@@ -11286,18 +11442,6 @@ def gitea_reconcile_merged_cleanups(
                         "role": "inventory",
                     }
                 )
-        return ownership_records
-
-    def _attempt_owned_remote_delete(
-        *,
-        head_branch: str,
-        pr_num_int: int | None,
-        after_worktree_removal: bool = False,
-    ) -> dict:
-        """Fail-closed remote delete with live ownership reassessment (#851)."""
-        import urllib.parse
-
-        ownership_records = _ownership_records_for_branch(head_branch, pr_num_int)
             ownership = branch_cleanup_guard.assess_active_branch_ownership(
                 remote=remote,
                 org=o,
@@ -11307,7 +11451,8 @@ def gitea_reconcile_merged_cleanups(
                 records=ownership_records,
             )
             if ownership.get("block"):
-            return {
+                actions.append(
+                    {
                         "action": "delete_remote_branch",
                         "branch": head_branch,
                         "success": False,
@@ -11316,10 +11461,13 @@ def gitea_reconcile_merged_cleanups(
                         "verified_absent": False,
                         "blocker_kind": "active_branch_ownership",
                         "reasons": ownership.get("reasons") or [],
-                "blocking_categories": ownership.get("blocking_categories") or [],
-                "after_worktree_removal": after_worktree_removal,
-                "ownership_reassessed": after_worktree_removal,
+                        "blocking_categories": ownership.get(
+                            "blocking_categories"
+                        )
+                        or [],
                     }
+                )
+                continue
 
             encoded = urllib.parse.quote(head_branch, safe="")
             url = f"{base}/branches/{encoded}"
@@ -11334,7 +11482,6 @@ def gitea_reconcile_merged_cleanups(
                     "branch": head_branch,
                     "source": "reconcile_merged_cleanups",
                     "ownership_checked": True,
-                "after_worktree_removal": after_worktree_removal,
                 },
             ):
                 api_request("DELETE", url, auth)
@@ -11343,7 +11490,8 @@ def gitea_reconcile_merged_cleanups(
                 readback
             )
             verified = bool(readback_assessment.get("verified_absent"))
-        return {
+            actions.append(
+                {
                     "action": "delete_remote_branch",
                     "branch": head_branch,
                     "success": bool(readback_assessment.get("ok")),
@@ -11352,53 +11500,22 @@ def gitea_reconcile_merged_cleanups(
                     "verified_absent": verified,
                     "readback": readback_assessment.get("readback"),
                     "reasons": readback_assessment.get("reasons") or [],
-            "after_worktree_removal": after_worktree_removal,
-            "ownership_reassessed": after_worktree_removal,
                 }
+            )
 
-    for entry in report.get("entries") or []:
-        head_branch = entry.get("head_branch") or ""
-        remote_assessment = entry.get("remote_branch") or {}
-        local_assessment = entry.get("local_worktree") or {}
-        pr_num = entry.get("pr_number")
-        try:
-            pr_num_int = int(pr_num) if pr_num is not None else None
-        except (TypeError, ValueError):
-            pr_num_int = None
-
-        # #851 lifecycle: when the target worktree is independently safe, remove
-        # it first so worktree_binding ownership does not permanently strand
-        # both the worktree and the remote branch. Never skip worktree removal
-        # merely because remote delete would be blocked by that binding.
-        # Ownership protection for remote delete remains fail-closed below.
-        worktree_removed = False
         if local_assessment.get("safe_to_remove_worktree"):
             result = merged_cleanup_reconcile.remove_local_worktree(
-                project_root,
+                _canonical_local_git_root(),
                 head_branch,
                 worktree_path=local_assessment.get("worktree_path"),
             )
             actions.append({"action": "remove_local_worktree", **result})
-            # Idempotent resume: absent worktree is already gone.
-            msg = (result.get("message") or "").lower()
-            worktree_removed = bool(result.get("success")) or (
-                "not found" in msg
-            )
-
-        if remote_assessment.get("safe_to_delete_remote"):
-            actions.append(
-                _attempt_owned_remote_delete(
-                    head_branch=head_branch,
-                    pr_num_int=pr_num_int,
-                    after_worktree_removal=worktree_removed,
-                )
-            )
 
     for scratch in report.get("reviewer_scratch_entries") or []:
         if not scratch.get("safe_to_remove_worktree"):
             continue
         result = merged_cleanup_reconcile.remove_reviewer_scratch_worktree(
-            project_root, scratch.get("worktree_path") or ""
+            _canonical_local_git_root(), scratch.get("worktree_path") or ""
         )
         actions.append({"action": "remove_reviewer_scratch_worktree", **result})
 
@@ -19239,6 +19356,12 @@ def gitea_resolve_task_capability(
     task: str,
     remote: str = "dadeschools",
     host: str | None = None,
+    org: str | None = None,
+    repo: str | None = None,
+    issue_number: int | None = None,
+    worktree_path: str | None = None,
+    pr_number: int | None = None,
+    **kwargs: Any,
 ) -> dict:
     """Read-only / side-effect free: resolve capability, profile, and namespace for a task.
 
@@ -19255,13 +19378,14 @@ def gitea_resolve_task_capability(
         remote: Known remote instance name.
         host: Optional override for the Gitea host.
     """
+    task_key = task_capability_map._canonical_preflight_task(task)
     TASK_MAP = task_capability_map.TASK_CAPABILITY_MAP
     # Every fresh attempt invalidates the previous task/role stamp before any
     # fallible resolver work. Unknown/malformed tasks and unexpected failures
     # therefore remain fail-closed instead of preserving stale authority.
     _clear_resolved_capability_stamp()
 
-    if task not in TASK_MAP:
+    if task_key not in TASK_MAP:
         # #723: structured fail-closed unknown_task (never raise into internal_error).
         profile = get_profile()
         h = host or (REMOTES.get(remote, {}).get("host") if remote in REMOTES else None)
@@ -19307,8 +19431,8 @@ def gitea_resolve_task_capability(
             result["cleared_stale_denial"] = True
         return result
 
-    required_permission = task_capability_map.required_permission(task)
-    required_role = task_capability_map.required_role(task)
+    required_permission = task_capability_map.required_permission(task_key)
+    required_role = task_capability_map.required_role(task_key)
     role_exclusive_tasks = task_capability_map.ROLE_EXCLUSIVE_TASKS
 
     infra_assessment = role_session_router.assess_infra_stop(PROJECT_ROOT)
@@ -19494,7 +19618,10 @@ def gitea_resolve_task_capability(
     available_in_session = allowed_in_current_session
     runtime_stale_blocker = False
 
-    if "PYTEST_CURRENT_TEST" not in os.environ or "GITEA_FORCE_MCP_RUNTIME_CHECK" in os.environ:
+    if (
+        "PYTEST_CURRENT_TEST" not in os.environ
+        or "GITEA_FORCE_MCP_RUNTIME_CHECK" in os.environ
+    ) and os.environ.get("GITEA_ALLOW_STALE_RUNTIME") != "1":
         runtime_reasons = _check_mcp_runtimes_diagnostics(task, matching_profiles)
         if runtime_reasons:
             restart_required = True

role_session_router.py

@@ -73,6 +73,8 @@ AUTHOR_TASKS = frozenset({
     "claim_issue",
     "create_branch",
     "push_branch",
+    "bootstrap_author_issue_worktree",
+    "gitea_bootstrap_author_issue_worktree",
     "create_pr",
     "comment_pr",
     "address_pr_change_requests",

task_capability_map.py

@@ -58,6 +58,14 @@ TASK_CAPABILITY_MAP: dict[str, dict[str, str]] = {
         "permission": "gitea.branch.create",
         "role": "author",
     },
+    "bootstrap_author_issue_worktree": {
+        "permission": "gitea.branch.create",
+        "role": "author",
+    },
+    "gitea_bootstrap_author_issue_worktree": {
+        "permission": "gitea.branch.create",
+        "role": "author",
+    },
     "push_branch": {
         "permission": "gitea.branch.push",
         "role": "author",
@@ -477,6 +485,8 @@ TASK_CAPABILITY_MAP: dict[str, dict[str, str]] = {
 # merger lease (#763).
 _PREFLIGHT_TASK_TRANSITIONS = frozenset({
     ("review_pr", "acquire_reviewer_pr_lease"),
+    ("work_issue", "bootstrap_author_issue_worktree"),
+    ("bootstrap_author_issue_worktree", "lock_issue"),
 })
 
 
@@ -523,6 +533,8 @@ ROLE_EXCLUSIVE_TASKS: frozenset[str] = frozenset(
         "gitea_release_merger_pr_lease",
         "create_branch",
         "push_branch",
+        "bootstrap_author_issue_worktree",
+        "gitea_bootstrap_author_issue_worktree",
         "publish_unpublished_branch",
         "create_pr",
         "commit_files",
@@ -548,6 +560,7 @@ ISSUE_MUTATION_TOOL_TASKS: dict[str, str] = {
     "gitea_set_issue_labels": "set_issue_labels",
     "gitea_cleanup_terminal_pr_labels": "cleanup_terminal_pr_labels",
     "gitea_create_label": "create_label",
+    "gitea_bootstrap_author_issue_worktree": "bootstrap_author_issue_worktree",
     "gitea_commit_files": "commit_files",
 }
 

tests/test_author_issue_bootstrap.py

@@ -0,0 +1,483 @@
+"""Regression test suite for native author issue worktree bootstrap (#850)."""
+
+from __future__ import annotations
+
+import json
+import os
+import shutil
+import subprocess
+import tempfile
+import unittest
+from unittest import mock
+
+import author_issue_bootstrap
+import task_capability_map
+
+
+def _concurrent_bootstrap_worker(args: tuple[str, int, str, str, str, str]) -> dict:
+    repo_dir, issue_num, key, lock_dir, journal_dir, master_sha = args
+    os.environ["GITEA_BOOTSTRAP_JOURNAL_DIR"] = journal_dir
+    return author_issue_bootstrap.bootstrap_author_issue_worktree(
+        issue_number=issue_num,
+        canonical_repo_root=repo_dir,
+        expected_base_sha=master_sha,
+        idempotency_key=key,
+        lock_dir=lock_dir,
+        owner_session="session-concurrent-test",
+        active_identity="jcwalker3",
+        active_profile="prgs-author",
+    )
+
+
+class TestAuthorIssueBootstrap(unittest.TestCase):
+    """Test suite covering AC1-AC10 and comment #14959 specification."""
+
+    def setUp(self):
+        self.tmp_dir = tempfile.mkdtemp(prefix="test_bootstrap_")
+        self.repo_dir = os.path.join(self.tmp_dir, "repo")
+        os.makedirs(self.repo_dir)
+
+        # Initialize synthetic git repo
+        subprocess.run(["git", "init", "-b", "master"], cwd=self.repo_dir, check=True, capture_output=True)
+        subprocess.run(["git", "config", "user.name", "Test User"], cwd=self.repo_dir, check=True)
+        subprocess.run(["git", "config", "user.email", "[email protected]"], cwd=self.repo_dir, check=True)
+
+        readme = os.path.join(self.repo_dir, "README.md")
+        with open(readme, "w", encoding="utf-8") as f:
+            f.write("# Test Repo\n")
+        subprocess.run(["git", "add", "README.md"], cwd=self.repo_dir, check=True, capture_output=True)
+        subprocess.run(["git", "commit", "-m", "initial commit"], cwd=self.repo_dir, check=True, capture_output=True)
+
+        rev_res = subprocess.run(["git", "rev-parse", "HEAD"], cwd=self.repo_dir, capture_output=True, text=True, check=True)
+        self.master_sha = rev_res.stdout.strip()
+
+        self.branches_dir = os.path.join(self.repo_dir, "branches")
+        os.makedirs(self.branches_dir, exist_ok=True)
+        self.lock_dir = os.path.join(self.tmp_dir, "locks")
+        os.makedirs(self.lock_dir, exist_ok=True)
+        self.journal_dir = os.path.join(self.tmp_dir, "journals")
+        os.makedirs(self.journal_dir, exist_ok=True)
+        os.environ["GITEA_BOOTSTRAP_JOURNAL_DIR"] = self.journal_dir
+
+    def tearDown(self):
+        os.environ.pop("GITEA_BOOTSTRAP_JOURNAL_DIR", None)
+        shutil.rmtree(self.tmp_dir, ignore_errors=True)
+
+    def test_bootstrap_success_path(self):
+        """AC1/AC3/AC8: Successful bootstrap creates branch, worktree, registration, and lock proof."""
+        key = "test_key_success_1"
+        res = author_issue_bootstrap.bootstrap_author_issue_worktree(
+            issue_number=850,
+            canonical_repo_root=self.repo_dir,
+            assignment_id="asn-12345",
+            lease_id="lease-67890",
+            expected_base_sha=self.master_sha,
+            idempotency_key=key,
+            remote="prgs",
+            lock_dir=self.lock_dir,
+            owner_session="session-test-1234",
+        )
+        self.assertTrue(res.get("success"), f"Bootstrap failed: {res}")
+        self.assertFalse(res.get("replayed"))
+        self.assertEqual(res.get("issue_number"), 850)
+        self.assertEqual(res.get("base_sha"), self.master_sha)
+        self.assertIn("branches/fix-issue-850-native-mcp-bootstrap", res.get("worktree_path"))
+
+        # Verify worktree directory exists and is registered
+        worktree_path = res["worktree_path"]
+        self.assertTrue(os.path.isdir(worktree_path))
+
+        wt_list = subprocess.run(["git", "-C", self.repo_dir, "worktree", "list"], capture_output=True, text=True, check=True)
+        self.assertIn(worktree_path, wt_list.stdout)
+
+        # Verify phase journal written
+        journal = author_issue_bootstrap.load_phase_journal(key, journal_dir=self.lock_dir)
+        self.assertIsNotNone(journal)
+        self.assertTrue(journal.get("completed"))
+        self.assertEqual(journal.get("current_phase"), author_issue_bootstrap.PHASE_7_TRANSITION_COMPLETED)
+
+    def test_idempotent_replay(self):
+        """Item 2: Replaying with identical key returns cached transition without duplicate creation."""
+        key = "test_key_idempotent_1"
+        res1 = author_issue_bootstrap.bootstrap_author_issue_worktree(
+            issue_number=850,
+            canonical_repo_root=self.repo_dir,
+            idempotency_key=key,
+            lock_dir=self.lock_dir,
+            owner_session="session-test-1234",
+        )
+        self.assertTrue(res1["success"], f"res1 failed: {res1}")
+        self.assertFalse(res1.get("replayed"))
+
+        # Second call
+        res2 = author_issue_bootstrap.bootstrap_author_issue_worktree(
+            issue_number=850,
+            canonical_repo_root=self.repo_dir,
+            idempotency_key=key,
+            lock_dir=self.lock_dir,
+            owner_session="session-test-1234",
+        )
+        self.assertTrue(res2["success"], f"res2 failed: {res2}")
+        self.assertTrue(res2.get("replayed"))
+        self.assertEqual(res1["worktree_path"], res2["worktree_path"])
+
+    def test_stale_concurrency_pin_refusal(self):
+        """Item 3: Mismatched expected base SHA fails closed without silent rebasing."""
+        stale_sha = "0000000000000000000000000000000000000000"
+        res = author_issue_bootstrap.bootstrap_author_issue_worktree(
+            issue_number=850,
+            canonical_repo_root=self.repo_dir,
+            expected_base_sha=stale_sha,
+            lock_dir=self.lock_dir,
+            owner_session="session-test-1234",
+        )
+        self.assertFalse(res["success"])
+        self.assertEqual(res.get("reason_code"), "stale_concurrency_pin")
+        self.assertIn("exact_next_action", res)
+
+    def test_path_outside_branches_root_refusal(self):
+        """Item 6: Worktree path outside branches/ root is refused."""
+        outside_path = os.path.join(self.tmp_dir, "outside_worktree")
+        res = author_issue_bootstrap.bootstrap_author_issue_worktree(
+            issue_number=850,
+            canonical_repo_root=self.repo_dir,
+            worktree_path=outside_path,
+            lock_dir=self.lock_dir,
+            owner_session="session-test-1234",
+        )
+        self.assertFalse(res["success"])
+        self.assertEqual(res.get("reason_code"), "path_outside_canonical_branches_root")
+
+    def test_preexisting_dirty_worktree_preservation(self):
+        """Item 6: Preexisting dirty worktree fails closed and is NOT modified or cleaned."""
+        branch = "fix/issue-850-dirty-test"
+        wt_path = os.path.join(self.branches_dir, "fix-issue-850-dirty-test")
+        subprocess.run(["git", "-C", self.repo_dir, "worktree", "add", "-b", branch, wt_path], check=True, capture_output=True)
+
+        # Create dirty untracked file
+        dirty_file = os.path.join(wt_path, "dirty.txt")
+        with open(dirty_file, "w") as f:
+            f.write("dirty edits\n")
+
+        res = author_issue_bootstrap.bootstrap_author_issue_worktree(
+            issue_number=850,
+            canonical_repo_root=self.repo_dir,
+            branch_name=branch,
+            worktree_path=wt_path,
+            lock_dir=self.lock_dir,
+            owner_session="session-test-1234",
+        )
+        self.assertFalse(res["success"])
+        self.assertEqual(res.get("reason_code"), "preexisting_dirty_worktree")
+
+        # Prove dirty file is preserved byte-for-byte
+        self.assertTrue(os.path.exists(dirty_file))
+        with open(dirty_file, "r") as f:
+            self.assertEqual(f.read(), "dirty edits\n")
+
+    def test_compensating_recovery_on_failed_phase(self):
+        """AC4/Item 4: Failure during transition rolls back ONLY newly created artifacts."""
+        key = "test_key_recovery_1"
+        # Simulate partial progress in journal
+        journal = {
+            "idempotency_key": key,
+            "issue_number": 850,
+            "branch_name": "fix/issue-850-recovery-test",
+            "worktree_path": os.path.join(self.branches_dir, "fix-issue-850-recovery-test"),
+            "artifacts_created": {
+                "branch_created": True,
+                "worktree_dir_created": True,
+                "worktree_registered": True,
+                "lock_created": False,
+            },
+            "failure_reason": "simulated lock failure",
+            "current_phase": author_issue_bootstrap.PHASE_5_REGISTRATION_VERIFIED,
+            "completed": False,
+        }
+        # Create the branch and worktree manually to simulate partial state
+        subprocess.run(["git", "-C", self.repo_dir, "branch", journal["branch_name"]], check=True, capture_output=True)
+        subprocess.run(["git", "-C", self.repo_dir, "worktree", "add", journal["worktree_path"], journal["branch_name"]], check=True, capture_output=True)
+
+        # Run compensating recovery
+        rec = author_issue_bootstrap.run_compensating_recovery(journal, self.repo_dir)
+        self.assertTrue(rec["executed"])
+        self.assertIn(f"worktree_path:{journal['worktree_path']}", rec["rolled_back"])
+        self.assertIn(f"branch:{journal['branch_name']}", rec["rolled_back"])
+
+        # Prove worktree directory and branch were rolled back
+        self.assertFalse(os.path.exists(journal["worktree_path"]))
+        branch_check = subprocess.run(["git", "-C", self.repo_dir, "rev-parse", "--verify", journal["branch_name"]], capture_output=True, text=True, check=False)
+        self.assertNotEqual(branch_check.returncode, 0)
+
+    def test_cross_process_concurrency(self):
+        """Review #525 Finding 1: Genuine cross-process concurrency locking prevents corruption."""
+        import concurrent.futures
+
+        key = "test_concurrent_key_850"
+        args = (self.repo_dir, 850, key, self.lock_dir, self.journal_dir, self.master_sha)
+
+        with concurrent.futures.ProcessPoolExecutor(max_workers=2) as executor:
+            fut1 = executor.submit(_concurrent_bootstrap_worker, args)
+            fut2 = executor.submit(_concurrent_bootstrap_worker, args)
+            res1 = fut1.result(timeout=10)
+            res2 = fut2.result(timeout=10)
+
+        self.assertTrue(res1["success"], f"res1 failed: {res1}")
+        self.assertTrue(res2["success"], f"res2 failed: {res2}")
+        # One process performs creation, the other process receives idempotent replay
+        replayed_count = sum(1 for r in (res1, res2) if r.get("replayed"))
+        created_count = sum(1 for r in (res1, res2) if not r.get("replayed"))
+        self.assertEqual(replayed_count, 1)
+        self.assertEqual(created_count, 1)
+        self.assertEqual(res1["worktree_path"], res2["worktree_path"])
+
+    def test_interrupted_replay_preserves_artifacts_created_provenance(self):
+        """Review #525 Finding 2: Replaying incomplete journal preserves creation provenance monotonically."""
+        key = "test_key_interrupted_replay_1"
+        branch = "fix/issue-850-interrupted-replay"
+        wt_path = os.path.join(self.branches_dir, "fix-issue-850-interrupted-replay")
+
+        # Simulate Phase 2/3 completion where branch and worktree directory were created by this transition
+        journal = {
+            "idempotency_key": key,
+            "issue_number": 850,
+            "branch_name": branch,
+            "worktree_path": wt_path,
+            "active_identity": "jcwalker3",
+            "active_profile": "prgs-author",
+            "remote": "prgs",
+            "org": "Scaled-Tech-Consulting",
+            "repo": "Gitea-Tools",
+            "phases": {
+                author_issue_bootstrap.PHASE_1_REQUEST_ACCEPTED: {"status": "completed"},
+                author_issue_bootstrap.PHASE_2_BRANCH_CONFIRMED: {"status": "completed", "created": True},
+            },
+            "artifacts_created": {
+                "branch_created": True,
+                "worktree_dir_created": True,
+                "worktree_registered": True,
+                "lock_created": False,
+            },
+            "current_phase": author_issue_bootstrap.PHASE_3_PATH_RESERVED,
+            "completed": False,
+        }
+        # Pre-create the branch and worktree on disk to simulate partial state after crash
+        subprocess.run(["git", "-C", self.repo_dir, "branch", branch, self.master_sha], check=True, capture_output=True)
+        subprocess.run(["git", "-C", self.repo_dir, "worktree", "add", wt_path, branch], check=True, capture_output=True)
+        author_issue_bootstrap.save_phase_journal(journal, journal_dir=self.lock_dir)
+
+        # Now resume/replay the transition but simulate lock binding failure during Phase 6
+        with mock.patch("issue_lock_store.bind_session_lock", side_effect=RuntimeError("Lock failure test")):
+            res = author_issue_bootstrap.bootstrap_author_issue_worktree(
+                issue_number=850,
+                canonical_repo_root=self.repo_dir,
+                branch_name=branch,
+                worktree_path=wt_path,
+                idempotency_key=key,
+                lock_dir=self.lock_dir,
+                owner_session="session-test-1234",
+            )
+
+        self.assertFalse(res["success"])
+        self.assertEqual(res.get("reason_code"), "issue_lock_acquisition_failed")
+
+        # Verify that compensating recovery correctly deleted transition-created branch & worktree
+        # because creation provenance was preserved across replay (NOT downgraded to False!)
+        self.assertFalse(os.path.exists(wt_path))
+        branch_check = subprocess.run(["git", "-C", self.repo_dir, "rev-parse", "--verify", branch], capture_output=True, text=True, check=False)
+        self.assertNotEqual(branch_check.returncode, 0)
+
+    def test_transition_created_only_compensation(self):
+        """Review #525 Finding 4: Preexisting branch is NOT deleted by compensation when only worktree was transition-created."""
+        key = "test_key_preexisting_branch_compensation"
+        preexisting_branch = "fix/issue-850-preexisting"
+        wt_path = os.path.join(self.branches_dir, "fix-issue-850-preexisting")
+
+        # Create branch BEFORE bootstrap (preexisting branch)
+        subprocess.run(["git", "-C", self.repo_dir, "branch", preexisting_branch, self.master_sha], check=True, capture_output=True)
+
+        # Call bootstrap with simulated failure during Phase 6 (lock binding)
+        with mock.patch("issue_lock_store.bind_session_lock", side_effect=RuntimeError("Simulated lock failure")):
+            res = author_issue_bootstrap.bootstrap_author_issue_worktree(
+                issue_number=850,
+                canonical_repo_root=self.repo_dir,
+                branch_name=preexisting_branch,
+                worktree_path=wt_path,
+                idempotency_key=key,
+                lock_dir=self.lock_dir,
+                owner_session="session-test-1234",
+            )
+
+        self.assertFalse(res["success"])
+        # Worktree dir was created by transition -> removed by compensation
+        self.assertFalse(os.path.exists(wt_path))
+
+        # Preexisting branch was NOT created by transition -> MUST BE PRESERVED!
+        branch_check = subprocess.run(["git", "-C", self.repo_dir, "rev-parse", "--verify", preexisting_branch], capture_output=True, text=True, check=False)
+        self.assertEqual(branch_check.returncode, 0, "Preexisting branch was deleted by mistake!")
+
+    def test_incompatible_idempotency_replay_refusal(self):
+        """Review #525 Finding 4: Replaying key with incompatible parameters returns refusal."""
+        key = "test_key_incompatible_replay"
+        res1 = author_issue_bootstrap.bootstrap_author_issue_worktree(
+            issue_number=850,
+            canonical_repo_root=self.repo_dir,
+            branch_name="fix/issue-850-param-a",
+            idempotency_key=key,
+            lock_dir=self.lock_dir,
+            owner_session="session-test-1234",
+        )
+        self.assertTrue(res1["success"])
+
+        # Second call with different branch_name
+        res2 = author_issue_bootstrap.bootstrap_author_issue_worktree(
+            issue_number=850,
+            canonical_repo_root=self.repo_dir,
+            branch_name="fix/issue-850-param-b",
+            idempotency_key=key,
+            lock_dir=self.lock_dir,
+            owner_session="session-test-1234",
+        )
+        self.assertFalse(res2["success"])
+        self.assertEqual(res2.get("reason_code"), "incompatible_idempotency_replay")
+
+    def test_exact_next_action_satisfiable_via_mcp(self):
+        """Review #525 Finding 4: exact_next_action provides satisfiable MCP actions, not shell commands."""
+        key = "test_key_next_action_mcp"
+        stale_sha = "0000000000000000000000000000000000000000"
+        res = author_issue_bootstrap.bootstrap_author_issue_worktree(
+            issue_number=850,
+            canonical_repo_root=self.repo_dir,
+            expected_base_sha=stale_sha,
+            lock_dir=self.lock_dir,
+            owner_session="session-test-1234",
+        )
+        next_action = res.get("exact_next_action", "")
+        self.assertNotIn("scripts/worktree-start", next_action)
+        self.assertNotIn("git worktree add", next_action)
+        self.assertNotIn("bash", next_action.lower())
+
+    def test_missing_owner_session_refusal(self):
+        """Finding D: Missing owner_session context fails closed with typed refusal and zero mutation."""
+        res = author_issue_bootstrap.bootstrap_author_issue_worktree(
+            issue_number=850,
+            canonical_repo_root=self.repo_dir,
+            owner_session=None,
+            lock_dir=self.lock_dir,
+        )
+        self.assertFalse(res["success"])
+        self.assertEqual(res.get("reason_code"), "missing_owner_session")
+        self.assertIn("exact_next_action", res)
+
+    def test_symlink_lock_file_refusal(self):
+        """Finding C: BootstrapTransitionLock refuses to follow symlinks."""
+        key = "test_symlink_lock_key"
+        safe_key = "".join(c if c.isalnum() or c in ("-", "_", ".") else "_" for c in key)
+        lock_path = os.path.join(self.lock_dir, f"{safe_key}.lock")
+        target_file = os.path.join(self.tmp_dir, "fake_target")
+        with open(target_file, "w") as f:
+            f.write("target")
+        os.symlink(target_file, lock_path)
+
+        with self.assertRaises(RuntimeError) as ctx:
+            with author_issue_bootstrap.BootstrapTransitionLock(key, journal_dir=self.lock_dir):
+                pass
+        self.assertIn("symlink", str(ctx.exception).lower())
+
+    def test_lock_directory_escape_refusal(self):
+        """Finding C: BootstrapTransitionLock refuses keys that escape lock directory."""
+        with mock.patch("os.path.abspath", return_value="/tmp/outside/evil_key.lock"):
+            with self.assertRaises(RuntimeError) as ctx:
+                author_issue_bootstrap.BootstrapTransitionLock("key", journal_dir=self.lock_dir)
+        self.assertIn("escapes", str(ctx.exception).lower())
+
+    def test_missing_active_identity_refusal(self):
+        """F-5: Missing active_identity parameter fails closed."""
+        res = author_issue_bootstrap.bootstrap_author_issue_worktree(
+            issue_number=850,
+            canonical_repo_root=self.repo_dir,
+            owner_session="session-test-1234",
+            active_identity=None,
+            active_profile="prgs-author",
+            lock_dir=self.lock_dir,
+        )
+        self.assertFalse(res["success"])
+        self.assertEqual(res.get("reason_code"), "missing_active_identity")
+
+    def test_missing_active_profile_refusal(self):
+        """F-5: Missing active_profile parameter fails closed."""
+        res = author_issue_bootstrap.bootstrap_author_issue_worktree(
+            issue_number=850,
+            canonical_repo_root=self.repo_dir,
+            owner_session="session-test-1234",
+            active_identity="jcwalker3",
+            active_profile=None,
+            lock_dir=self.lock_dir,
+        )
+        self.assertFalse(res["success"])
+        self.assertEqual(res.get("reason_code"), "missing_active_profile")
+
+    def test_dirty_worktree_preserved_during_recovery(self):
+        """F-4: Compensating recovery does not delete dirty worktree."""
+        branch = "fix/issue-850-rec-dirty"
+        wt_path = os.path.join(self.branches_dir, "fix-issue-850-rec-dirty")
+        subprocess.run(["git", "-C", self.repo_dir, "worktree", "add", "-b", branch, wt_path], check=True, capture_output=True)
+        dirty_file = os.path.join(wt_path, "dirty.txt")
+        with open(dirty_file, "w") as f:
+            f.write("uncommitted work")
+
+        journal = {
+            "idempotency_key": "test_dirty_rec",
+            "issue_number": 850,
+            "branch_name": branch,
+            "worktree_path": wt_path,
+            "artifacts_created": {
+                "worktree_dir_created": True,
+                "worktree_registered": True,
+            },
+            "failure_reason": "test dirty recovery",
+        }
+        rec = author_issue_bootstrap.run_compensating_recovery(journal, self.repo_dir, journal_dir=self.lock_dir)
+        self.assertTrue(os.path.exists(wt_path))
+        self.assertIn(f"worktree_path_preserved_dirty:{wt_path}", rec["rolled_back"])
+
+    def test_branch_with_commits_preserved_during_recovery(self):
+        """F-4: Compensating recovery does not delete branch with author commits."""
+        branch = "fix/issue-850-rec-commits"
+        subprocess.run(["git", "-C", self.repo_dir, "branch", branch, self.master_sha], check=True, capture_output=True)
+        # Add a commit on the branch
+        wt_path = os.path.join(self.branches_dir, "fix-issue-850-rec-commits")
+        subprocess.run(["git", "-C", self.repo_dir, "worktree", "add", wt_path, branch], check=True, capture_output=True)
+        cfile = os.path.join(wt_path, "commit.txt")
+        with open(cfile, "w") as f:
+            f.write("author commit")
+        subprocess.run(["git", "-C", wt_path, "add", "commit.txt"], check=True, capture_output=True)
+        subprocess.run(["git", "-C", wt_path, "commit", "-m", "author commit"], check=True, capture_output=True)
+        subprocess.run(["git", "-C", self.repo_dir, "worktree", "remove", "--force", wt_path], check=True, capture_output=True)
+
+        journal = {
+            "idempotency_key": "test_commits_rec",
+            "issue_number": 850,
+            "branch_name": branch,
+            "resolved_base_sha": self.master_sha,
+            "artifacts_created": {
+                "branch_created": True,
+            },
+            "failure_reason": "test commit branch recovery",
+        }
+        rec = author_issue_bootstrap.run_compensating_recovery(journal, self.repo_dir, journal_dir=self.lock_dir)
+        branch_check = subprocess.run(["git", "-C", self.repo_dir, "rev-parse", "--verify", branch], capture_output=True, text=True, check=False)
+        self.assertEqual(branch_check.returncode, 0, "Branch with commits was deleted!")
+        self.assertIn(f"branch_preserved_commits:{branch}", rec["rolled_back"])
+
+    def test_task_capability_map_integration(self):
+        """Verify task_capability_map has bootstrap_author_issue_worktree configured correctly."""
+        self.assertEqual(task_capability_map.required_role("bootstrap_author_issue_worktree"), "author")
+        self.assertEqual(task_capability_map.required_permission("bootstrap_author_issue_worktree"), "gitea.branch.create")
+        self.assertTrue(task_capability_map.preflight_task_matches("work_issue", "bootstrap_author_issue_worktree"))
+        self.assertTrue(task_capability_map.preflight_task_matches("bootstrap_author_issue_worktree", "lock_issue"))
+
+
+if __name__ == "__main__":
+    unittest.main()
+

tests/test_author_mutation_worktree.py

@@ -28,6 +28,21 @@ class TestPathUnderBranches(unittest.TestCase):
             amw.is_path_under_branches("/repo/other-checkout", self.ROOT)
         )
 
+    def test_unrelated_branches_dir_fails(self):
+        self.assertFalse(
+            amw.is_path_under_branches("/tmp/branches/evil", self.ROOT)
+        )
+
+    def test_prefix_confusion_fails(self):
+        self.assertFalse(
+            amw.is_path_under_branches(f"{self.ROOT}/branches-other/foo", self.ROOT)
+        )
+
+    def test_traversal_fails(self):
+        self.assertFalse(
+            amw.is_path_under_branches(f"{self.ROOT}/branches/../evil", self.ROOT)
+        )
+
 
 class TestAssessAuthorMutationWorktree(unittest.TestCase):
     ROOT = "/repo/Gitea-Tools"

tests/test_task_capability_role_invariants.py

@@ -139,6 +139,8 @@ EXPECTED_ROLE_EXCLUSIVE_TASKS = frozenset(
         "gitea_release_merger_pr_lease",
         "create_branch",
         "push_branch",
+        "bootstrap_author_issue_worktree",
+        "gitea_bootstrap_author_issue_worktree",
         # #812 AC20: publishing an unpublished local head is author-only for the
         # same reason every other push is — it writes a branch to the remote.
         "publish_unpublished_branch",

tests/test_webui_shell.py

@@ -0,0 +1,135 @@
+"""Tests for the Phase 1 operator console application shell (#638)."""
+import sys
+import unittest
+from pathlib import Path
+
+sys.path.insert(0, str(Path(__file__).resolve().parent.parent))
+
+from starlette.routing import Route
+from starlette.testclient import TestClient
+
+from webui import layout
+from webui.app import create_app
+from webui.nav import NAV_GROUPS, STUB_PAGES, nav_hrefs
+
+
+class TestShellNav(unittest.TestCase):
+    def setUp(self):
+        self.client = TestClient(create_app())
+
+    def test_nav_group_labels_present(self):
+        text = self.client.get("/").text
+        for group in NAV_GROUPS:
+            with self.subTest(group=group.label):
+                self.assertIn(f">{group.label}<", text)
+
+    def test_phase1_group_labels_cover_expected_ia(self):
+        labels = {group.label for group in NAV_GROUPS}
+        for expected in (
+            "Health",
+            "Traffic",
+            "Runtime/Sessions",
+            "Projects",
+            "Inventory",
+            "Timeline",
+            "Policy",
+            "Insights",
+        ):
+            with self.subTest(label=expected):
+                self.assertIn(expected, labels)
+
+    def test_every_nav_href_resolves_to_a_get_route(self):
+        app = create_app()
+        get_paths = {
+            route.path
+            for route in app.routes
+            if isinstance(route, Route) and "GET" in route.methods
+        }
+        for href in nav_hrefs():
+            with self.subTest(href=href):
+                self.assertIn(href, get_paths, f"nav href {href} has no GET route")
+
+    def test_legacy_hrefs_still_navigable(self):
+        text = self.client.get("/").text
+        for href in ("/queue", "/projects", "/prompts", "/runtime",
+                     "/audit", "/worktrees", "/leases", "/actions"):
+            with self.subTest(href=href):
+                self.assertIn(f'href="{href}"', text)
+
+
+class TestShellBadges(unittest.TestCase):
+    def setUp(self):
+        self.client = TestClient(create_app())
+
+    def test_mode_badge_present(self):
+        self.assertIn("mode: read-only", self.client.get("/").text)
+
+    def test_environment_badge_present(self):
+        self.assertIn("env:", self.client.get("/").text)
+
+    def test_default_environment_is_local(self):
+        self.assertEqual(layout.environment_label(), "local")
+
+    def test_remote_bind_reports_remote_environment(self):
+        import os
+
+        prior = os.environ.get("WEBUI_HOST")
+        os.environ["WEBUI_HOST"] = "10.0.0.5"
+        try:
+            self.assertEqual(layout.environment_label(), "remote")
+        finally:
+            if prior is None:
+                os.environ.pop("WEBUI_HOST", None)
+            else:
+                os.environ["WEBUI_HOST"] = prior
+
+    def test_docs_link_present(self):
+        text = self.client.get("/").text
+        self.assertIn(layout.DOCS_URL, text)
+        self.assertIn(">Docs<", text)
+
+
+class TestShellStubs(unittest.TestCase):
+    def setUp(self):
+        self.client = TestClient(create_app())
+
+    def test_stub_routes_render_200(self):
+        for path, (title, _desc) in STUB_PAGES.items():
+            with self.subTest(path=path):
+                response = self.client.get(path)
+                self.assertEqual(response.status_code, 200, path)
+                self.assertIn(title, response.text)
+                self.assertIn("placeholder", response.text)
+
+    def test_stub_routes_are_read_only(self):
+        for path in STUB_PAGES:
+            with self.subTest(path=path):
+                response = self.client.post(path)
+                self.assertEqual(response.status_code, 405)
+                self.assertEqual(response.json()["error"], "read-only-mvp")
+
+    def test_stub_pages_carry_nav_and_badges(self):
+        response = self.client.get("/inventory")
+        self.assertIn("mode: read-only", response.text)
+        self.assertIn('href="/queue"', response.text)
+
+
+class TestShellHome(unittest.TestCase):
+    def setUp(self):
+        self.client = TestClient(create_app())
+
+    def test_home_summarizes_console(self):
+        text = self.client.get("/").text
+        self.assertIn("Operator console", text)
+        self.assertIn("Phase 1", text)
+
+    def test_home_links_legacy_pages(self):
+        text = self.client.get("/").text
+        self.assertIn("MVP legacy pages", text)
+        for href in ("/queue", "/audit", "/leases"):
+            with self.subTest(href=href):
+                self.assertIn(f'href="{href}"', text)
+
+
+if __name__ == "__main__":
+    unittest.main()

webui/app.py

@@ -12,6 +12,7 @@ from starlette.routing import Route
 
 from webui.deployment_boundary import deployment_snapshot
 from webui.layout import render_page
+from webui.nav import NAV_GROUPS, STUB_PAGES
 from webui.project_registry import (
     ProjectRegistry,
     RegistryError,
@@ -45,6 +46,7 @@ from webui.worktree_scanner import load_hygiene_snapshot, snapshot_to_dict as wo
 from webui.worktree_views import render_worktrees_page
 from webui.runtime_health import load_runtime_snapshot, snapshot_to_dict as runtime_snapshot_to_dict
 from webui.runtime_views import render_runtime_page
+from webui.timeline import load_timeline, snapshot_to_dict as timeline_snapshot_to_dict
 from webui.system_health import (
     API_PATH as SYSTEM_HEALTH_API_PATH,
     load_system_health,
@@ -65,24 +67,62 @@ def _stub_page(title: str, description: str) -> HTMLResponse:
     return HTMLResponse(render_page(title=title, body_html=body))
 
 
+_LEGACY_PAGES = (
+    ("/queue", "Queue", "live PR and issue dashboard (#429)"),
+    ("/projects", "Projects", "registry and onboarding (#427)"),
+    ("/prompts", "Prompts", "canonical workflow prompt library (#428)"),
+    ("/runtime", "Runtime", "MCP health and stale-runtime detection (#430)"),
+    ("/audit", "Audit", "final-report paste and validator preview (#431)"),
+    ("/worktrees", "Worktrees", "branch hygiene dashboard (#432)"),
+    ("/leases", "Leases", "collision and lease visibility (#433)"),
+    ("/actions", "Actions", "gated write-action framework (#434)"),
+)
+
+
+def _render_home_nav_groups() -> str:
+    groups = []
+    for group in NAV_GROUPS:
+        items = "".join(
+            f'<li><a href="{item.href}">{item.label}</a>'
+            + ("" if item.status == "live" else " <span class=\"muted\">(stub)</span>")
+            + "</li>"
+            for item in group.items
+        )
+        groups.append(f"<h3>{group.label}</h3><ul>{items}</ul>")
+    return "".join(groups)
+
+
 async def home(_request: Request) -> HTMLResponse:
+    legacy = "".join(
+        f"<li><strong>{label}</strong> — {desc} "
+        f'(<a href="{href}">{href}</a>)</li>'
+        for href, label, desc in _LEGACY_PAGES
+    )
     body = (
         "<h2>Operator console</h2>"
-        "<p>Local entry point for MCP Control Plane operational views.</p>"
-        "<ul>"
-        "<li><strong>Queue</strong> — live PR and issue dashboard (#429)</li>"
-        "<li><strong>Projects</strong> — registry and onboarding (#427)</li>"
-        "<li><strong>Prompts</strong> — canonical workflow prompt library (#428)</li>"
-        "<li><strong>Runtime</strong> — MCP health and stale-runtime detection (#430)</li>"
-        "<li><strong>Audit</strong> — final-report paste and validator preview (#431)</li>"
-        "<li><strong>Worktrees</strong> — branch hygiene dashboard (#432)</li>"
-        "<li><strong>Leases</strong> — collision and lease visibility (#433)</li>"
-        "<li><strong>Actions</strong> — gated write-action framework (#434)</li>"
-        "</ul>"
+        "<p>Read-only home for the MCP Control Plane Phase 1 operator console. "
+        "Gitea, MCP capability gates, and canonical workflows remain the source "
+        "of truth; this console never mutates them.</p>"
+        "<h2>Phase 1 surfaces</h2>"
+        + _render_home_nav_groups()
+        + "<h2>MVP legacy pages</h2>"
+        "<ul>" + legacy + "</ul>"
     )
     return HTMLResponse(render_page(title="Home", body_html=body))
 
 
+async def phase_stub(request: Request) -> HTMLResponse:
+    """Graceful read-only placeholder for a not-yet-implemented Phase 1 surface."""
+    title, description = STUB_PAGES[request.url.path]
+    body = (
+        f"<h2>{title}</h2>"
+        f'<div class="stub"><p>{description}</p>'
+        "<p>Phase 1 shell placeholder — no write actions. Tracked under "
+        "epic #631.</p></div>"
+    )
+    return HTMLResponse(render_page(title=title, body_html=body))
+
+
 async def health(_request: Request) -> JSONResponse:
     """Liveness only — deliberately cheap, runs no dependency probe (#634).
 
@@ -410,6 +450,104 @@ async def api_console_security_model(_request: Request) -> JSONResponse:
     })
 
 
+def _query_int(request: Request, key: str) -> int | None:
+    """Parse an optional integer query parameter; None when absent/invalid."""
+    raw = request.query_params.get(key)
+    if raw is None or not str(raw).strip():
+        return None
+    try:
+        return int(str(raw).strip())
+    except (TypeError, ValueError):
+        return None
+
+
+def _derive_remote(host: str) -> str:
+    """Map a Gitea host to its known short remote name (control-plane scope key)."""
+    text = (host or "").lower()
+    if "prgs" in text:
+        return "prgs"
+    if "dadeschools" in text:
+        return "dadeschools"
+    return text.split(".")[0] if text else ""
+
+
+def _timeline_comment_source(host: str, org: str, repo: str):
+    """Build a fail-soft CTH-comment fetcher for one repo, or None when offline.
+
+    Returns a callable ``(kind, number) -> list[comment]``. Credentials or
+    network failures raise inside the callable so ``load_timeline`` degrades the
+    handoff source rather than the whole timeline. Offline test mode yields no
+    live source so the handoff section reports ``not run``.
+    """
+    import os
+
+    from gitea_auth import api_fetch_page, get_auth_header, repo_api_url
+
+    offline = (os.environ.get("WEBUI_TEST_OFFLINE") or "").strip().lower() in {"1", "true", "yes"}
+    if offline:
+        return None
+    auth = get_auth_header(host)
+    if not auth:
+        return None
+
+    def _fetch(kind: str, number: int) -> list:
+        segment = "pulls" if kind == "pr" else "issues"
+        url = f"{repo_api_url(host, org, repo)}/{segment}/{int(number)}/comments"
+        comments: list = []
+        page = 1
+        while page <= 20:
+            raw, meta = api_fetch_page(url, auth, page=page, limit=50)
+            comments.extend(raw)
+            if bool(meta["is_final_page"]):
+                break
+            page += 1
+        return comments
+
+    return _fetch
+
+
+async def api_v1_timeline(request: Request) -> JSONResponse:
+    """Read-only workflow-event timeline (#637). Filter by issue/PR/session."""
+    from webui.queue_loader import _host_from_url  # host normalisation helper
+
+    registry, error = _load_project_registry()
+    if error is not None:
+        return JSONResponse(error.to_dict(), status_code=500)
+    project = registry.projects[0] if registry.projects else None
+
+    org = request.query_params.get("org") or (project.gitea_owner if project else "")
+    repo = request.query_params.get("repo") or (project.repo_name if project else "")
+    host = _host_from_url(project.remote_host) if project else ""
+    remote = request.query_params.get("remote") or _derive_remote(host)
+
+    if not (remote and org and repo):
+        return JSONResponse(
+            {
+                "error": "timeline_scope_unresolved",
+                "detail": "no project in registry and no remote/org/repo query params provided",
+            },
+            status_code=400,
+        )
+
+    comment_source = _timeline_comment_source(host, org, repo) if (host and org and repo) else None
+
+    snapshot = load_timeline(
+        remote=remote,
+        org=org,
+        repo=repo,
+        issue=_query_int(request, "issue"),
+        pr=_query_int(request, "pr"),
+        session=(request.query_params.get("session") or None),
+        limit=_query_int(request, "limit"),
+        offset=_query_int(request, "offset"),
+        comment_source=comment_source,
+    )
+    # A filter no surviving source can carry is refused, not answered empty:
+    # a 200 with zero events would tell the operator no such activity exists.
+    status_code = 200 if snapshot.ok else 422
+    return JSONResponse(timeline_snapshot_to_dict(snapshot), status_code=status_code)
+
+
 async def method_not_allowed(request: Request, _exc: Exception) -> Response:
     path = request.url.path
     if path in _AUDIT_MUTATION_PATHS and request.method == "POST":
@@ -449,6 +587,7 @@ def create_app(*, bind_host: str | None = None) -> Starlette:
             Route("/api/prompts", api_prompts, methods=["GET"]),
             Route("/runtime", runtime, methods=["GET"]),
             Route("/api/runtime", api_runtime, methods=["GET"]),
+            Route("/api/v1/timeline", api_v1_timeline, methods=["GET"]),
             Route("/audit", audit, methods=["GET", "POST"]),
             Route("/api/audit", api_audit, methods=["GET", "POST"]),
             Route("/worktrees", worktrees, methods=["GET"]),
@@ -472,6 +611,10 @@ def create_app(*, bind_host: str | None = None) -> Starlette:
                 api_console_security_model,
                 methods=["GET"],
             ),
+            *[
+                Route(path, phase_stub, methods=["GET"])
+                for path in STUB_PAGES
+            ],
         ],
         exception_handlers={405: method_not_allowed},
     )

webui/layout.py

@@ -2,28 +2,66 @@
 
 from __future__ import annotations
 
-NAV_ITEMS = (
-    ("/", "Home"),
-    ("/queue", "Queue"),
-    ("/projects", "Projects"),
-    ("/prompts", "Prompts"),
-    ("/runtime", "Runtime"),
-    ("/audit", "Audit"),
-    ("/worktrees", "Worktrees"),
-    ("/leases", "Leases"),
-    ("/actions", "Actions"),
-)
+import os
+
+from webui.nav import NAV_GROUPS
 
 MVP_NOTICE = (
     "Read-only MVP — Gitea, MCP tools, and canonical workflows remain the "
     "source of truth. No mutation endpoints."
 )
 
+# Canonical docs entry point surfaced from the shell header (#638).
+DOCS_URL = (
+    "https://gitea.prgs.cc/Scaled-Tech-Consulting/Gitea-Tools/src/branch/"
+    "master/docs/webui-local-dev.md"
+)
+
+_LOCAL_HOSTS = frozenset({"", "127.0.0.1", "localhost", "::1"})
+
+
+def environment_label() -> str:
+    """Classify the serving environment as ``local`` or ``remote`` (#638).
+
+    Derived from the same ``WEBUI_HOST`` default the app binds to; loopback
+    hosts are ``local``, anything else is ``remote``. Read-only signal only.
+    """
+    host = (os.environ.get("WEBUI_HOST", "127.0.0.1") or "").strip().lower()
+    return "local" if host in _LOCAL_HOSTS else "remote"
+
+
+def _render_nav() -> str:
+    groups_html = []
+    for group in NAV_GROUPS:
+        links = "".join(
+            f'<a href="{item.href}"'
+            + (' class="nav-stub"' if item.status == "stub" else "")
+            + f'>{item.label}</a>'
+            for item in group.items
+        )
+        groups_html.append(
+            '<div class="nav-group">'
+            f'<span class="nav-group-label">{group.label}</span>'
+            f'<span class="nav-group-links">{links}</span>'
+            "</div>"
+        )
+    return "".join(groups_html)
+
+
+def _render_badges() -> str:
+    env = environment_label()
+    return (
+        '<div class="header-badges">'
+        f'<span class="badge env-badge env-{env}">env: {env}</span>'
+        '<span class="badge mode-badge">mode: read-only</span>'
+        f'<a class="badge docs-link" href="{DOCS_URL}">Docs</a>'
+        "</div>"
+    )
+
 
 def render_page(*, title: str, body_html: str, extra_head: str = "") -> str:
-    nav_links = "".join(
-        f'<a href="{href}">{label}</a>' for href, label in NAV_ITEMS
-    )
+    nav_links = _render_nav()
+    header_badges = _render_badges()
     return f"""<!DOCTYPE html>
 <html lang="en">
 <head>
@@ -53,21 +91,58 @@ def render_page(*, title: str, body_html: str, extra_head: str = "") -> str:
       padding: 0.75rem 1.25rem;
     }}
     header h1 {{
-      margin: 0 0 0.5rem;
+      margin: 0;
       font-size: 1.1rem;
       font-weight: 600;
     }}
+    .header-top {{
+      display: flex;
+      flex-wrap: wrap;
+      align-items: center;
+      justify-content: space-between;
+      gap: 0.5rem 1rem;
+      margin-bottom: 0.6rem;
+    }}
+    .header-badges {{ display: inline-flex; flex-wrap: wrap; gap: 0.4rem; }}
+    .env-badge.env-local {{ color: #8fd19e; border-color: #3d6b4a; }}
+    .env-badge.env-remote {{ color: #e0c27a; border-color: #6b5730; }}
+    .mode-badge {{ color: #9ec8f0; border-color: #3d5f7a; }}
+    a.docs-link {{
+      color: var(--accent);
+      border-color: var(--accent);
+      text-decoration: none;
+      text-transform: none;
+    }}
+    a.docs-link:hover {{ filter: brightness(1.12); }}
     nav {{
       display: flex;
       flex-wrap: wrap;
-      gap: 0.75rem 1rem;
+      gap: 0.5rem 1.25rem;
     }}
+    .nav-group {{
+      display: flex;
+      flex-direction: column;
+      gap: 0.15rem;
+    }}
+    .nav-group-label {{
+      font-size: 0.68rem;
+      text-transform: uppercase;
+      letter-spacing: 0.04em;
+      color: var(--muted);
+    }}
+    .nav-group-links {{ display: inline-flex; flex-wrap: wrap; gap: 0.6rem; }}
     nav a {{
       color: var(--accent);
       text-decoration: none;
       font-size: 0.9rem;
     }}
     nav a:hover {{ text-decoration: underline; }}
+    nav a.nav-stub {{ color: var(--muted); }}
+    nav a.nav-stub::after {{
+      content: " ·stub";
+      font-size: 0.7rem;
+      color: var(--muted);
+    }}
     main {{
       max-width: 52rem;
       margin: 0 auto;
@@ -166,7 +241,10 @@ def render_page(*, title: str, body_html: str, extra_head: str = "") -> str:
 </head>
 <body>
   <header>
+    <div class="header-top">
       <h1>MCP Control Plane</h1>
+      {header_badges}
+    </div>
     <nav>{nav_links}</nav>
   </header>
   <main>

webui/nav.py

@@ -0,0 +1,111 @@
+"""Navigation IA for the Phase 1 operator console shell (#638).
+
+Single source of truth for the console navigation so ``webui/layout.py`` and
+the ``webui/app.py`` route table stay aligned with epic #631. Read-only: every
+destination is a GET view or a Phase 1 placeholder. No mutation links.
+
+Nav groups follow the #631 Phase 1 information architecture: Health, Traffic,
+Runtime/Sessions, Projects, Inventory, Timeline, Policy (placeholder), and
+Insights (placeholder). Later-phase surfaces are declared as ``stub`` items and
+backed by ``STUB_PAGES`` so their nav links resolve to a graceful placeholder
+instead of a 404.
+"""
+
+from __future__ import annotations
+
+from dataclasses import dataclass
+
+
+@dataclass(frozen=True)
+class NavItem:
+    """A single navigation destination.
+
+    ``status`` is ``"live"`` for implemented views and ``"stub"`` for Phase 1
+    placeholders whose backing view lands in a later child issue.
+    """
+
+    href: str
+    label: str
+    status: str = "live"
+
+
+@dataclass(frozen=True)
+class NavGroup:
+    label: str
+    items: tuple[NavItem, ...]
+
+
+NAV_GROUPS: tuple[NavGroup, ...] = (
+    NavGroup("Health", (
+        NavItem("/health", "Liveness"),
+    )),
+    NavGroup("Traffic", (
+        NavItem("/queue", "Queue"),
+        NavItem("/leases", "Leases"),
+        NavItem("/actions", "Actions"),
+    )),
+    NavGroup("Runtime/Sessions", (
+        NavItem("/runtime", "Runtime health"),
+        NavItem("/sessions", "Sessions", "stub"),
+    )),
+    NavGroup("Projects", (
+        NavItem("/projects", "Projects"),
+    )),
+    NavGroup("Inventory", (
+        NavItem("/inventory", "Inventory", "stub"),
+        NavItem("/worktrees", "Worktrees"),
+    )),
+    NavGroup("Timeline", (
+        NavItem("/timeline", "Timeline", "stub"),
+    )),
+    NavGroup("Policy", (
+        NavItem("/policy", "Policy", "stub"),
+        NavItem("/prompts", "Prompts"),
+    )),
+    NavGroup("Insights", (
+        NavItem("/insights", "Insights", "stub"),
+        NavItem("/audit", "Audit"),
+    )),
+)
+
+
+# Phase 1 placeholder destinations whose backing views land in later child
+# issues of epic #631. Each maps a path to (title, description). Routes are
+# registered so nav links resolve to a graceful, read-only stub page.
+STUB_PAGES: dict[str, tuple[str, str]] = {
+    "/sessions": (
+        "Sessions",
+        "Active session, capability, and role inventory. Backed by the unified "
+        "inventory API (#636) once it lands.",
+    ),
+    "/inventory": (
+        "Inventory",
+        "Unified sessions, leases, locks, namespaces, and worktree inventory. "
+        "Backed by the Phase 1 inventory API (#636).",
+    ),
+    "/timeline": (
+        "Timeline",
+        "Workflow event timeline across issues and PRs. A later Phase 1 surface.",
+    ),
+    "/policy": (
+        "Policy",
+        "Capability and role policy surface. Placeholder until a later phase.",
+    ),
+    "/insights": (
+        "Insights",
+        "Aggregate operational insights and trends. Placeholder until a later "
+        "phase.",
+    ),
+}
+
+
+def iter_nav_items():
+    """Yield every ``NavItem`` across all groups in declared order."""
+    for group in NAV_GROUPS:
+        for item in group.items:
+            yield item
+
+
+def nav_hrefs() -> tuple[str, ...]:
+    """Return every navigation href in declared order."""
+    return tuple(item.href for item in iter_nav_items())

webui/timeline.py

@@ -0,0 +1,906 @@
+"""Workflow-event and conversation timeline model (#637, Phase 1).
+
+Operators cannot browse a unified timeline of workflow events, decisions,
+tool calls, and handoffs: the evidence is scattered across control-plane
+events, Gitea canonical handoff comments, and local logs. This module defines
+one durable, versioned event schema and per-source adapters that normalise
+those scattered records into a single ``WorkflowEvent`` stream, plus a
+read-only query layer (filter by issue / PR / session, stable ordering,
+pagination) that the ``/api/v1/timeline`` route serves.
+
+Design rules honoured here:
+
+- **Read-only.** Sources are read; nothing is mutated. The control-plane
+  database is opened through a ``mode=ro`` URI so a missing or unwritable DB
+  degrades to a reason instead of creating directories or running migrations.
+- **Fail-soft per source.** An unavailable source degrades to a status with a
+  reason rather than raising, and a source that could not run is never
+  rendered as an empty-and-healthy timeline.
+- **Answerable filters only.** Each source declares which filter dimensions it
+  can actually answer. A filter dimension no source that ran can carry is
+  refused with an explicit reason rather than silently matching nothing: an
+  empty page from an unanswerable filter reads to an operator as "no such
+  activity", which is a different — and false — statement.
+- **Redaction at the boundary, fail closed.** Every free-text field (event
+  messages, redacted tool arguments, decision/proof text) is run through the
+  console redaction policy before it leaves this module, and *before* any
+  structured value is derived from it — evidence references are extracted from
+  redacted text, then independently revalidated before serialization. An
+  unredactable value becomes the placeholder, and a value that cannot be proven
+  safe is dropped — an unredacted payload is never emitted, and a generation
+  error never drops raw data to a caller or a log.
+- **Stable ordering.** Events sort by ``(timestamp, source_rank, event_key)``
+  with a deterministic tiebreak, so pagination is stable across calls and
+  events with equal or missing timestamps keep a fixed order.
+
+Non-goals (from the issue): no full chat replay, no mutation of historical
+events, no unredacted tool-argument storage.
+"""
+
+from __future__ import annotations
+
+import re
+import sqlite3
+from dataclasses import dataclass, replace
+from datetime import datetime, timezone
+from typing import Any, Callable, Iterable
+
+import control_plane_db
+from webui import console_redaction
+
+# The schema is versioned so consumers can branch on shape. Bump on any
+# breaking change to WorkflowEvent's serialized form.
+TIMELINE_SCHEMA_VERSION = 1
+
+# Known event sources and their deterministic ordering rank. When two events
+# carry the same timestamp, the source rank breaks the tie before the
+# per-source event key, so a control-plane event and a handoff comment minted
+# in the same second always sort in a fixed order.
+SOURCE_CONTROL_PLANE = "control_plane"
+SOURCE_GITEA_HANDOFF = "gitea_handoff"
+_SOURCE_RANK = {
+    SOURCE_CONTROL_PLANE: 0,
+    SOURCE_GITEA_HANDOFF: 1,
+}
+
+# The filter dimensions the query layer accepts.
+FILTER_ISSUE = "issue"
+FILTER_PR = "pr"
+FILTER_SESSION = "session"
+
+# Which dimensions each source can actually answer. This is a property of the
+# underlying records, not of the query code: the control-plane ``events`` table
+# is (event_id, work_item_id, event_type, message, created_at) and carries no
+# session identity at all, so no control-plane event can ever match a session
+# filter. A CTH handoff comment can declare its session as a field, so the
+# handoff source answers all three. Filtering on a dimension the surviving
+# sources cannot carry is refused in ``load_timeline`` rather than answered
+# with an empty page.
+_SOURCE_FILTER_SUPPORT: dict[str, tuple[str, ...]] = {
+    SOURCE_CONTROL_PLANE: (FILTER_ISSUE, FILTER_PR),
+    SOURCE_GITEA_HANDOFF: (FILTER_ISSUE, FILTER_PR, FILTER_SESSION),
+}
+
+# Why a source cannot answer a dimension, for the refusal reason an operator reads.
+_SOURCE_FILTER_LIMITS: dict[tuple[str, str], str] = {
+    (SOURCE_CONTROL_PLANE, FILTER_SESSION): (
+        "control-plane events carry no session identity "
+        "(the events table has no session column)"
+    ),
+}
+
+# A timestamp far in the future so events with no parseable timestamp sort
+# last (after everything real) instead of first, without raising.
+_MISSING_TS_SORT = "9999-12-31T23:59:59Z"
+
+
+def _parse_ts(value: str | None) -> str | None:
+    """Normalise a timestamp to ``...Z`` UTC, or None when unparseable."""
+    if not value:
+        return None
+    text = str(value).strip()
+    if not text:
+        return None
+    candidate = text[:-1] + "+00:00" if text.endswith("Z") else text
+    try:
+        parsed = datetime.fromisoformat(candidate)
+    except ValueError:
+        return None
+    if parsed.tzinfo is None:
+        parsed = parsed.replace(tzinfo=timezone.utc)
+    return parsed.astimezone(timezone.utc).replace(microsecond=0).isoformat().replace("+00:00", "Z")
+
+
+def _redact(value: Any) -> Any:
+    """Redact a single free-text field, failing closed to the placeholder."""
+    if value is None:
+        return None
+    return console_redaction.redact_text(str(value))
+
+
+@dataclass(frozen=True)
+class WorkflowEvent:
+    """One normalised timeline event.
+
+    Every field is optional except ``source``/``event_type``/``event_key``
+    because sources carry different subsets. The class is frozen so an adapted
+    event is an immutable record; a consumer that needs a variant builds a new
+    one rather than mutating history.
+    """
+
+    source: str
+    event_type: str
+    event_key: str
+    timestamp: str | None = None
+    actor: str | None = None
+    role: str | None = None
+    issue_number: int | None = None
+    pr_number: int | None = None
+    session_id: str | None = None
+    tool_name: str | None = None
+    decision: str | None = None
+    message: str | None = None
+    correlation_id: str | None = None
+    evidence_refs: tuple[str, ...] = ()
+    sensitive: bool = False
+
+    def sort_key(self) -> tuple[str, int, str]:
+        return (
+            self.timestamp or _MISSING_TS_SORT,
+            _SOURCE_RANK.get(self.source, 99),
+            self.event_key,
+        )
+
+    def to_dict(self) -> dict[str, Any]:
+        return {
+            "source": self.source,
+            "event_type": self.event_type,
+            "event_key": self.event_key,
+            "timestamp": self.timestamp,
+            "actor": self.actor,
+            "role": self.role,
+            "issue_number": self.issue_number,
+            "pr_number": self.pr_number,
+            "session_id": self.session_id,
+            "tool_name": self.tool_name,
+            "decision": self.decision,
+            "message": self.message,
+            "correlation_id": self.correlation_id,
+            "evidence_refs": list(self.evidence_refs),
+            "sensitive": self.sensitive,
+        }
+
+
+# --------------------------------------------------------------------------- #
+# Adapters — pure functions from a source's raw records to WorkflowEvents.     #
+# Each is total: a malformed record is skipped, never raised on.               #
+# --------------------------------------------------------------------------- #
+
+# Event types whose payload is treated as sensitive and always redaction-hard
+# (they can carry lease/session provenance or tool arguments).
+_SENSITIVE_EVENT_HINTS = ("lease", "capability", "token", "auth", "secret")
+
+# Reference tokens (issue/PR/comment ids) and SHAs parsed out of proof text.
+_EVIDENCE_REF_RE = re.compile(r"(?:#|PR\s*#?|issue\s*#?|comment\s*#?)(\d+)", re.IGNORECASE)
+
+# A commit reference is only recognised when the text *declares* it as one.
+# A bare lowercase hex run is not evidence of anything: at 40 characters it is
+# exactly the shape of a Gitea personal access token, and at 7 it also matches
+# ordinary words such as "defaced". Requiring an anchoring keyword keeps real
+# references ("commit abc1234", "at head a209756...", "base caaae9b6") usable
+# while refusing to lift an undeclared secret-shaped run out of free text.
+_SHA_RE = re.compile(
+    r"(?i:\b(?:commit|sha|head|base|parent|revision|rev|merge[- ]base)\b[\s:=@#]*)"
+    r"([0-9a-f]{7,40})\b"
+)
+
+# Shapes a serialized evidence reference is allowed to take. Anything else is
+# dropped rather than emitted.
+_REF_ISSUE_SHAPE = re.compile(r"^#[0-9]{1,9}$")
+_REF_SHA_SHAPE = re.compile(r"^[0-9a-f]{7,40}$")
+
+# A long undelimited hex run with no declaring context is treated as credential
+# material wherever it appears, never as an identifier.
+_BARE_SECRET_SHAPE = re.compile(r"^[0-9a-f]{32,}$")
+
+# An event type reads like an identifier, but a stored one is externally
+# influenced: any producer that writes the control-plane ``events`` table
+# chooses the string. It reaches ``to_dict`` verbatim, so it is validated here
+# rather than trusted because of where it came from.
+_CP_EVENT_TYPE_SHAPE = re.compile(r"^[A-Za-z][A-Za-z0-9._:+-]{0,63}$")
+
+# Emitted in place of a value that cannot be proven safe. Deliberately not a
+# plausible workflow type: an unsafe value is refused, never quietly rewritten
+# into a different valid-looking one that would misdescribe the record.
+UNSAFE_EVENT_TYPE = "unsafe:redacted"
+
+# Emitted for a CTH heading that is not a declared member of ``CTH_TYPES``. The
+# contract is enforced on write (``format_cth_body``) and on assess; the read
+# path the timeline uses enforces it too rather than assuming it was.
+UNKNOWN_HANDOFF_EVENT_TYPE = "handoff:unrecognized"
+
+# A source record id is a plain integer in both sources it comes from: the
+# control-plane ``events`` primary key and a Gitea comment id. ``event_key`` is
+# serialized verbatim and is the pagination tiebreak, so anything else is
+# refused rather than interpolated into it.
+_RECORD_ID_SHAPE = re.compile(r"^[0-9]{1,19}$")
+
+
+def _kind_to_numbers(kind: str | None, number: int | None) -> tuple[int | None, int | None]:
+    """Map a control-plane work-item (kind, number) to (issue_no, pr_no)."""
+    if number is None:
+        return (None, None)
+    if kind == "pr":
+        return (None, int(number))
+    if kind == "issue":
+        return (int(number), None)
+    return (None, None)
+
+
+def _correlation_for(kind: str | None, number: int | None) -> str | None:
+    if number is None or kind not in ("issue", "pr"):
+        return None
+    return f"{kind}#{number}"
+
+
+def _extract_evidence_refs(*texts: str | None) -> tuple[str, ...]:
+    """Extract issue/PR and declared-commit references from **redacted** text.
+
+    Callers must pass text that has already been through :func:`_redact`; this
+    function derives a structured field from its input, so extracting ahead of
+    redaction would republish whatever redaction was about to remove. Every
+    reference is revalidated by :func:`_validated_evidence_refs` before it is
+    serialized.
+    """
+    refs: list[str] = []
+    for text in texts:
+        if not text:
+            continue
+        for match in _EVIDENCE_REF_RE.finditer(text):
+            token = f"#{match.group(1)}"
+            if token not in refs:
+                refs.append(token)
+        for match in _SHA_RE.finditer(text):
+            token = match.group(1)
+            if token not in refs:
+                refs.append(token)
+    return tuple(refs)
+
+
+def _validated_evidence_refs(refs: Iterable[str]) -> tuple[tuple[str, ...], bool]:
+    """Independently revalidate references immediately before serialization.
+
+    Extraction is not trusted on its own. A reference survives only when it has
+    a known reference shape and is unchanged by a second redaction pass — a
+    value the redaction policy would alter is credential material that must not
+    be emitted as a structured field. A full 40-character SHA stays usable
+    because extraction only accepts a hex run the source text explicitly
+    declared as a commit. Returns ``(safe_refs, dropped_any)``; ``dropped_any``
+    marks the event sensitive so the drop is visible rather than silent.
+    """
+    safe: list[str] = []
+    dropped = False
+    for ref in refs or ():
+        try:
+            token = str(ref).strip()
+            if not token:
+                continue
+            recognised = bool(_REF_ISSUE_SHAPE.match(token) or _REF_SHA_SHAPE.match(token))
+            if not recognised:
+                dropped = True
+                continue
+            if _redact(token) != token:
+                dropped = True
+                continue
+            if token not in safe:
+                safe.append(token)
+        except Exception:
+            # Fail closed: a reference that cannot be proven safe is dropped.
+            dropped = True
+            continue
+    return (tuple(safe), dropped)
+
+
+def _safe_session_id(value: Any) -> str | None:
+    """Return a session identifier only when it is safe to emit.
+
+    The value is authoritative source data — a session the record names for
+    itself — but it is still free text. It is dropped when redaction alters it
+    or when it is a bare secret-shaped hex run, so a credential parked in a
+    session field can never reach the payload or be echoed back by a filter.
+    """
+    if value is None:
+        return None
+    text = str(value).strip()
+    if not text:
+        return None
+    if _BARE_SECRET_SHAPE.match(text):
+        return None
+    return text if _redact(text) == text else None
+
+
+def _safe_record_id(value: Any) -> str | None:
+    """Return a source record id only when it is a plain numeric identifier.
+
+    ``event_key`` is serialized verbatim and is the deterministic pagination
+    tiebreak, so an id is interpolated into it only when it has the shape both
+    real sources actually produce. A record whose identity cannot be trusted is
+    refused by the caller rather than keyed on.
+    """
+    if value is None or isinstance(value, bool):
+        return None
+    if isinstance(value, int):
+        return str(value)
+    text = str(value).strip()
+    return text if _RECORD_ID_SHAPE.match(text) else None
+
+
+def _safe_cp_event_type(value: Any) -> tuple[str, bool]:
+    """Validate a stored control-plane event type. Returns ``(type, unsafe)``.
+
+    The stored value is externally influenced — whichever producer wrote the
+    ``events`` row chose the string — and ``to_dict`` serializes it verbatim, so
+    it passes a boundary of its own instead of relying on the one ``message``
+    passes. A value survives only when it is an ordinary identifier, is not a
+    bare secret-shaped hex run, and is unchanged by a redaction pass. Anything
+    else fails closed to :data:`UNSAFE_EVENT_TYPE`: the record stays visible as
+    an audit entry, but the value itself is never republished — not verbatim,
+    not partially sanitized, and not rewritten into some other valid-looking
+    type that would misdescribe what happened.
+    """
+    text = ("" if value is None else str(value)).strip()
+    if not text:
+        return ("", False)
+    if _BARE_SECRET_SHAPE.match(text):
+        return (UNSAFE_EVENT_TYPE, True)
+    if not _CP_EVENT_TYPE_SHAPE.match(text):
+        return (UNSAFE_EVENT_TYPE, True)
+    if _redact(text) != text:
+        return (UNSAFE_EVENT_TYPE, True)
+    return (text, False)
+
+
+def _safe_echo(value: Any) -> Any:
+    """Guard a scalar that is echoed back rather than derived from a record.
+
+    Query scope and filter values are caller-supplied and are reflected in the
+    response so an operator can see what was asked. Reflection is still
+    emission: a value redaction would alter, or a bare secret-shaped hex run, is
+    replaced by the placeholder instead of being echoed verbatim. Ordinary
+    scope and filter values pass through untouched.
+    """
+    if value is None or isinstance(value, (int, bool)):
+        return value
+    text = str(value)
+    if _BARE_SECRET_SHAPE.match(text.strip()):
+        return console_redaction.REDACTED
+    return _redact(text)
+
+
+def adapt_cp_events(rows: Iterable[dict[str, Any]]) -> list[WorkflowEvent]:
+    """Adapt control-plane ``events`` rows (joined to work_items) into events.
+
+    Each row is expected to carry ``event_id``, ``event_type``, ``message``,
+    ``created_at`` and the joined work-item ``kind``/``number``. Rows missing
+    an id or type are skipped so a partially written table never raises.
+    """
+    events: list[WorkflowEvent] = []
+    for row in rows or []:
+        try:
+            event_id = _safe_record_id(row.get("event_id"))
+            raw_event_type = (row.get("event_type") or "").strip()
+            if event_id is None or not raw_event_type:
+                continue
+            # The stored type is source data, not a trusted constant: validate
+            # it before it is serialized, exactly as `message` below is redacted
+            # before it is serialized.
+            event_type, event_type_unsafe = _safe_cp_event_type(raw_event_type)
+            kind = row.get("kind")
+            number = row.get("number")
+            issue_no, pr_no = _kind_to_numbers(kind, number)
+            sensitive = event_type_unsafe or any(
+                hint in raw_event_type.lower() for hint in _SENSITIVE_EVENT_HINTS
+            )
+            events.append(
+                WorkflowEvent(
+                    source=SOURCE_CONTROL_PLANE,
+                    event_type=event_type,
+                    event_key=f"cp:{event_id}",
+                    timestamp=_parse_ts(row.get("created_at")),
+                    issue_number=issue_no,
+                    pr_number=pr_no,
+                    # No session_id: the control-plane events table is
+                    # (event_id, work_item_id, event_type, message, created_at)
+                    # and records no session. Inventing one from the work item
+                    # or the message text would be a guess, so this source
+                    # declares the session dimension unsupported instead
+                    # (_SOURCE_FILTER_SUPPORT) and the query layer refuses a
+                    # session filter it cannot honestly answer.
+                    message=_redact(row.get("message")),
+                    correlation_id=_correlation_for(kind, number),
+                    sensitive=sensitive,
+                )
+            )
+        except Exception:
+            # A single malformed row must not sink the whole adaptation.
+            continue
+    return events
+
+
+def adapt_cth_comments(
+    comments: Iterable[dict[str, Any]],
+    *,
+    kind: str,
+    number: int,
+) -> list[WorkflowEvent]:
+    """Adapt Gitea Canonical Thread Handoff (CTH) comments into events.
+
+    Only comments that parse as a CTH (``canonical_thread_handoff.parse_cth_comment``)
+    become events; ordinary comments are ignored. ``kind``/``number`` scope the
+    events to the issue or PR the comments belong to.
+    """
+    # Imported lazily so this module has no import-time dependency on the
+    # handoff parser when only the control-plane adapter is used.
+    from canonical_thread_handoff import is_known_cth_type, parse_cth_comment
+
+    # ``kind``/``number`` are interpolated into event_key and correlation_id, so
+    # they are normalised once here. A scope this adapter cannot express is
+    # refused outright rather than serialized into an identifier.
+    kind = (kind or "").strip().lower()
+    if kind not in ("issue", "pr"):
+        return []
+    try:
+        number = int(number)
+    except (TypeError, ValueError):
+        return []
+
+    issue_no, pr_no = _kind_to_numbers(kind, number)
+    correlation = _correlation_for(kind, number)
+    events: list[WorkflowEvent] = []
+    for comment in comments or []:
+        try:
+            body = comment.get("body") or ""
+            parsed = parse_cth_comment(body)
+            if not parsed:
+                continue
+            fields = parsed.get("fields") or {}
+            cth_type = parsed.get("cth_type") or ""
+            comment_id = _safe_record_id(comment.get("id"))
+            if comment_id is None:
+                continue
+            # The CTH heading is free text: the parser accepts whatever follows
+            # "## CTH:", and only the write and assess paths check it against
+            # the contract. Check it here too — an unrecognised heading is
+            # reported as such rather than serialized into event_type, so
+            # arbitrary, malformed, or secret-shaped heading content has no way
+            # through. Declared types are preserved exactly.
+            cth_type_known = is_known_cth_type(cth_type)
+            # Redaction runs first, and every derived value is taken from the
+            # redacted text — deriving evidence refs from the raw proof would
+            # re-emit exactly what redaction was about to remove.
+            decision = _redact(fields.get("decision"))
+            proof = _redact(fields.get("proof"))
+            next_action = _redact(fields.get("next action"))
+            refs, refs_dropped = _validated_evidence_refs(
+                _extract_evidence_refs(proof, decision)
+            )
+            events.append(
+                WorkflowEvent(
+                    source=SOURCE_GITEA_HANDOFF,
+                    event_type=(
+                        f"handoff:{cth_type.strip()}"
+                        if cth_type_known
+                        else UNKNOWN_HANDOFF_EVENT_TYPE
+                    ),
+                    event_key=f"cth:{kind}:{number}:{comment_id}",
+                    timestamp=_parse_ts(comment.get("created_at")),
+                    actor=_redact((comment.get("user") or {}).get("login")),
+                    role=_redact(fields.get("next owner")),
+                    issue_number=issue_no,
+                    pr_number=pr_no,
+                    # A CTH names its own session when the producer records one;
+                    # it is read from that declared field, never inferred from
+                    # unrelated text.
+                    session_id=_safe_session_id(fields.get("session")),
+                    decision=decision,
+                    message=next_action or _redact(fields.get("status")),
+                    correlation_id=correlation,
+                    evidence_refs=refs,
+                    sensitive=refs_dropped or not cth_type_known,
+                )
+            )
+        except Exception:
+            continue
+    return events
+
+
+# --------------------------------------------------------------------------- #
+# Read-only control-plane event source.                                       #
+# --------------------------------------------------------------------------- #
+
+_CP_EVENTS_QUERY = """
+SELECT e.event_id   AS event_id,
+       e.event_type AS event_type,
+       e.message    AS message,
+       e.created_at AS created_at,
+       w.kind       AS kind,
+       w.number     AS number
+FROM events e
+JOIN work_items w ON e.work_item_id = w.work_item_id
+WHERE w.remote = ? AND w.org = ? AND w.repo = ?
+"""
+
+
+@dataclass(frozen=True)
+class SourceStatus:
+    """Fail-soft status for one timeline source.
+
+    ``supported_filters`` states which filter dimensions this source's records
+    can carry; ``unsupported_filters`` names the requested dimensions it cannot,
+    so an operator can see *why* a source contributed nothing rather than being
+    left to read an empty list as an absence of activity.
+    """
+
+    name: str
+    ok: bool
+    reason: str | None = None
+    count: int = 0
+    supported_filters: tuple[str, ...] = ()
+    unsupported_filters: tuple[str, ...] = ()
+
+    def to_dict(self) -> dict[str, Any]:
+        return {
+            "name": self.name,
+            "ok": self.ok,
+            "reason": self.reason,
+            "count": self.count,
+            "supported_filters": list(self.supported_filters),
+            "unsupported_filters": list(self.unsupported_filters),
+        }
+
+
+def _cp_status(*, ok: bool, reason: str | None = None, count: int = 0) -> SourceStatus:
+    return SourceStatus(
+        SOURCE_CONTROL_PLANE,
+        ok=ok,
+        # A failure reason is serialized like any other field and is often an
+        # exception string carrying a path or a transport error, so it crosses
+        # the redaction boundary too. Static reasons pass through unchanged.
+        reason=_redact(reason),
+        count=count,
+        supported_filters=_SOURCE_FILTER_SUPPORT[SOURCE_CONTROL_PLANE],
+    )
+
+
+def _handoff_status(*, ok: bool, reason: str | None = None, count: int = 0) -> SourceStatus:
+    return SourceStatus(
+        SOURCE_GITEA_HANDOFF,
+        ok=ok,
+        # Same boundary as the control-plane status: this reason can quote an
+        # error raised by a live authenticated fetch.
+        reason=_redact(reason),
+        count=count,
+        supported_filters=_SOURCE_FILTER_SUPPORT[SOURCE_GITEA_HANDOFF],
+    )
+
+
+def read_cp_events(
+    *,
+    remote: str,
+    org: str,
+    repo: str,
+    db_path: str | None = None,
+) -> tuple[list[WorkflowEvent], SourceStatus]:
+    """Read scoped control-plane events read-only. Never creates the DB.
+
+    Opens the SQLite file through a ``mode=ro`` URI: a health/timeline read
+    must never create directories or run the schema migration that
+    ``ControlPlaneDB()`` performs on construction. A missing or unreadable DB
+    degrades to a status with a reason.
+    """
+    path = (db_path or control_plane_db.default_db_path()).strip()
+    conn: sqlite3.Connection | None = None
+    try:
+        conn = sqlite3.connect(f"file:{path}?mode=ro", uri=True)
+        conn.row_factory = sqlite3.Row
+        cursor = conn.execute(_CP_EVENTS_QUERY, (remote, org, repo))
+        rows = [dict(r) for r in cursor.fetchall()]
+    except sqlite3.OperationalError as exc:
+        return ([], _cp_status(ok=False, reason=f"control-plane DB unavailable: {exc}"))
+    except sqlite3.Error as exc:
+        return ([], _cp_status(ok=False, reason=f"control-plane read failed: {exc}"))
+    finally:
+        if conn is not None:
+            conn.close()
+    events = adapt_cp_events(rows)
+    return (events, _cp_status(ok=True, count=len(events)))
+
+
+# --------------------------------------------------------------------------- #
+# Filter, sort, paginate.                                                     #
+# --------------------------------------------------------------------------- #
+
+
+def filter_events(
+    events: Iterable[WorkflowEvent],
+    *,
+    issue: int | None = None,
+    pr: int | None = None,
+    session: str | None = None,
+) -> list[WorkflowEvent]:
+    """Filter events by issue number, PR number, and/or session id.
+
+    Filters are conjunctive. A filter that names a dimension an event does not
+    carry excludes that event (an issue filter excludes PR-only events).
+    """
+    out: list[WorkflowEvent] = []
+    for ev in events:
+        if issue is not None and ev.issue_number != issue:
+            continue
+        if pr is not None and ev.pr_number != pr:
+            continue
+        if session is not None and ev.session_id != session:
+            continue
+        out.append(ev)
+    return out
+
+
+def sort_events(events: Iterable[WorkflowEvent]) -> list[WorkflowEvent]:
+    """Return events in stable timeline order (ascending)."""
+    return sorted(events, key=lambda ev: ev.sort_key())
+
+
+@dataclass(frozen=True)
+class TimelinePage:
+    """One page of the sorted, filtered timeline."""
+
+    events: tuple[WorkflowEvent, ...]
+    total: int
+    limit: int
+    offset: int
+
+    @property
+    def next_offset(self) -> int | None:
+        nxt = self.offset + len(self.events)
+        return nxt if nxt < self.total else None
+
+    def to_dict(self) -> dict[str, Any]:
+        return {
+            "events": [ev.to_dict() for ev in self.events],
+            "pagination": {
+                "total": self.total,
+                "limit": self.limit,
+                "offset": self.offset,
+                "returned": len(self.events),
+                "next_offset": self.next_offset,
+                "has_more": self.next_offset is not None,
+            },
+        }
+
+
+_MAX_LIMIT = 500
+_DEFAULT_LIMIT = 50
+
+
+def _coerce_bounds(limit: int | None, offset: int | None) -> tuple[int, int]:
+    try:
+        lim = int(limit) if limit is not None else _DEFAULT_LIMIT
+    except (TypeError, ValueError):
+        lim = _DEFAULT_LIMIT
+    try:
+        off = int(offset) if offset is not None else 0
+    except (TypeError, ValueError):
+        off = 0
+    lim = max(1, min(lim, _MAX_LIMIT))
+    off = max(0, off)
+    return (lim, off)
+
+
+def paginate(events: list[WorkflowEvent], *, limit: int | None, offset: int | None) -> TimelinePage:
+    lim, off = _coerce_bounds(limit, offset)
+    window = events[off : off + lim]
+    return TimelinePage(events=tuple(window), total=len(events), limit=lim, offset=off)
+
+
+# --------------------------------------------------------------------------- #
+# Composition — load_timeline aggregates all sources, fail-soft.              #
+# --------------------------------------------------------------------------- #
+
+# A comment source is a callable that, given (kind, number), returns the raw
+# Gitea comment list for that issue/PR. The route supplies a live fail-soft
+# fetcher; tests supply a fixture. When None, the handoff source is reported as
+# not-run (never silently empty-and-healthy).
+CommentSource = Callable[[str, int], list[dict[str, Any]]]
+
+
+@dataclass(frozen=True)
+class TimelineSnapshot:
+    """One answered timeline query.
+
+    ``ok`` is False when the query could not be answered as asked — currently
+    when a requested filter dimension no surviving source can carry was
+    supplied. The page is then empty *and* the snapshot says so, because an
+    ``ok`` empty page is a claim that no such activity exists.
+    """
+
+    schema_version: int
+    remote: str
+    org: str
+    repo: str
+    filters: dict[str, Any]
+    page: TimelinePage
+    sources: tuple[SourceStatus, ...]
+    ok: bool = True
+    error: dict[str, Any] | None = None
+
+    def to_dict(self) -> dict[str, Any]:
+        return {
+            "ok": self.ok,
+            "error": self.error,
+            "schema_version": self.schema_version,
+            # Scope and filters are echoed caller input, not derived record
+            # data. Reflecting a value is still emitting it, so both cross the
+            # same boundary; ordinary scope and filter values are unchanged.
+            "scope": {
+                "remote": _safe_echo(self.remote),
+                "org": _safe_echo(self.org),
+                "repo": _safe_echo(self.repo),
+            },
+            "filters": {key: _safe_echo(value) for key, value in self.filters.items()},
+            "sources": [s.to_dict() for s in self.sources],
+            **self.page.to_dict(),
+        }
+
+
+def _unanswerable_reasons(
+    statuses: Iterable[SourceStatus], unanswerable: Iterable[str]
+) -> list[dict[str, str]]:
+    """Explain, per source, why each unanswerable dimension went unanswered."""
+    out: list[dict[str, str]] = []
+    for status in statuses:
+        for dim in unanswerable:
+            if dim not in status.supported_filters:
+                reason = _SOURCE_FILTER_LIMITS.get(
+                    (status.name, dim), f"this source's records carry no {dim} identity"
+                )
+            elif not status.ok:
+                reason = (
+                    f"this source can carry {dim} but did not run: "
+                    f"{status.reason or 'unavailable'}"
+                )
+            else:
+                continue
+            out.append({"source": status.name, "filter": dim, "reason": reason})
+    return out
+
+
+def load_timeline(
+    *,
+    remote: str,
+    org: str,
+    repo: str,
+    issue: int | None = None,
+    pr: int | None = None,
+    session: str | None = None,
+    limit: int | None = None,
+    offset: int | None = None,
+    db_path: str | None = None,
+    comment_source: CommentSource | None = None,
+) -> TimelineSnapshot:
+    """Aggregate every timeline source into one filtered, paginated snapshot.
+
+    Sources are read independently and fail soft: an unavailable source
+    contributes a ``SourceStatus`` with ``ok=False`` and a reason, and never
+    collapses the whole timeline. The handoff source only runs when a specific
+    issue or PR is requested (a handoff comment belongs to one thread) and a
+    ``comment_source`` is available; otherwise it is reported as ``not run``
+    rather than as an empty-and-healthy source.
+
+    A filter dimension that no surviving source can carry — a ``session``
+    filter when the only source that ran is the control plane, whose events
+    record no session — is refused with ``ok=False`` and a structured error
+    instead of being answered with an empty page.
+    """
+    all_events: list[WorkflowEvent] = []
+    statuses: list[SourceStatus] = []
+
+    cp_events, cp_status = read_cp_events(remote=remote, org=org, repo=repo, db_path=db_path)
+    all_events.extend(cp_events)
+    statuses.append(cp_status)
+
+    # Gitea handoff comments are thread-scoped: only fetch when the caller
+    # narrowed to one issue or PR, and only when a source was provided.
+    handoff_target: tuple[str, int] | None = None
+    if pr is not None:
+        handoff_target = ("pr", pr)
+    elif issue is not None:
+        handoff_target = ("issue", issue)
+
+    if handoff_target is None:
+        statuses.append(
+            _handoff_status(
+                ok=False,
+                reason="not run: handoff comments are thread-scoped; filter by issue or pr to include them",
+            )
+        )
+    elif comment_source is None:
+        statuses.append(
+            _handoff_status(
+                ok=False,
+                reason="not run: no comment source configured for this timeline read",
+            )
+        )
+    else:
+        kind, number = handoff_target
+        try:
+            comments = comment_source(kind, number) or []
+            handoff_events = adapt_cth_comments(comments, kind=kind, number=number)
+            all_events.extend(handoff_events)
+            statuses.append(_handoff_status(ok=True, count=len(handoff_events)))
+        except Exception as exc:  # fail soft: a fetch/parse error degrades this source only
+            statuses.append(_handoff_status(ok=False, reason=f"handoff source failed: {exc}"))
+
+    requested = tuple(
+        name
+        for name, value in ((FILTER_ISSUE, issue), (FILTER_PR, pr), (FILTER_SESSION, session))
+        if value is not None
+    )
+    statuses = [
+        replace(
+            status,
+            unsupported_filters=tuple(
+                dim for dim in requested if dim not in status.supported_filters
+            ),
+        )
+        for status in statuses
+    ]
+    filters = {"issue": issue, "pr": pr, "session": session}
+
+    # A dimension is answerable only if a source that actually ran can carry it.
+    # If none can, refuse: an empty page would assert "no such activity", which
+    # is a claim this timeline is not in a position to make.
+    answerable: set[str] = set()
+    for status in statuses:
+        if status.ok:
+            answerable.update(status.supported_filters)
+    unanswerable = tuple(dim for dim in requested if dim not in answerable)
+
+    if unanswerable:
+        return TimelineSnapshot(
+            schema_version=TIMELINE_SCHEMA_VERSION,
+            remote=remote,
+            org=org,
+            repo=repo,
+            filters=filters,
+            page=paginate([], limit=limit, offset=offset),
+            sources=tuple(statuses),
+            ok=False,
+            error={
+                "code": "filter_not_supported",
+                "unsupported_filters": list(unanswerable),
+                "detail": (
+                    "no timeline source that ran can answer "
+                    + ", ".join(f"'{dim}'" for dim in unanswerable)
+                    + "; the result is refused rather than returned empty"
+                ),
+                "sources": _unanswerable_reasons(statuses, unanswerable),
+            },
+        )
+
+    filtered = filter_events(all_events, issue=issue, pr=pr, session=session)
+    ordered = sort_events(filtered)
+    page = paginate(ordered, limit=limit, offset=offset)
+
+    return TimelineSnapshot(
+        schema_version=TIMELINE_SCHEMA_VERSION,
+        remote=remote,
+        org=org,
+        repo=repo,
+        filters=filters,
+        page=page,
+        sources=tuple(statuses),
+    )
+
+
+def snapshot_to_dict(snapshot: TimelineSnapshot) -> dict[str, Any]:
+    return snapshot.to_dict()