test: align duplicate-gate and artifact tests with keyed lock store (#443)

Update lock-issue and duplicate-recheck tests to mock branch listing,
use GITEA_ISSUE_LOCK_DIR session binding, and satisfy create_pr
provenance/worktree guards after the keyed persistent lock store landed.

Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>

docs/llm-workflow-runbooks.md

@@ -274,12 +274,24 @@ is proven abandoned and the takeover is recorded.
 
 Gitea-Tools lease gates: `gitea_lock_issue` (fail-closed before author
 mutations), `status:in-progress`, and claim comments. `gitea_lock_issue`
-records an `author_issue_work` lease in the issue-lock payload with issue
-number, optional PR number, branch, worktree path, claimant identity/profile,
-created timestamp, expiry timestamp, and last heartbeat timestamp. An active
-same-issue/same-operation lease blocks duplicate work. An expired lease still
-blocks takeover until a recovery review records why the prior work is abandoned,
-completed, or unsafe to continue.
+records an `author_issue_work` lease in a keyed lock file under
+`GITEA_ISSUE_LOCK_DIR` (default `~/.cache/gitea-tools/issue-locks`), one file
+per `remote` + `org` + `repo` + `issue_number`. The current MCP session binds
+its active lock through a per-process pointer so concurrent repos/issues never
+share one overwrite-prone slot (#443).
+
+Each lock payload includes issue number, optional PR number, branch, worktree
+path, claimant identity/profile, created timestamp, expiry timestamp, and last
+heartbeat timestamp. An active same-issue/same-operation lease blocks duplicate
+work. An expired lease still blocks takeover until a recovery review records why
+the prior work is abandoned, completed, or unsafe to continue.
+
+**Do not manually seed `/tmp/gitea_issue_lock.json` or any lock file as a normal
+recovery path.** That global slot is deprecated and can clobber unrelated live
+leases (#438). After an MCP restart, call `gitea_lock_issue` again — own-branch
+adoption rebinds the session when the issue's exact branch already exists (#442).
+`gitea_create_pr` resolves the durable keyed lock by session pointer or by
+matching `head` branch without unsafe manual seeding.
 
 **Issue-lock recovery (#447):** Do not manually seed, restore, or delete
 `/tmp/gitea_issue_lock.json` as a normal recovery path. That file is global

gitea_mcp_server.py

@@ -539,10 +539,13 @@ import review_proofs  # noqa: E402
 import agent_temp_artifacts
 import issue_lock_worktree  # noqa: E402
 import issue_lock_provenance  # noqa: E402
+import issue_lock_store  # noqa: E402
+import issue_lock_adoption  # noqa: E402
 import already_landed_reconcile  # noqa: E402
 import author_mutation_worktree  # noqa: E402
 import issue_claim_heartbeat  # noqa: E402
 import issue_work_duplicate_gate  # noqa: E402
+import reviewer_pr_lease  # noqa: E402
 import merged_cleanup_reconcile  # noqa: E402
 import reconciler_profile  # noqa: E402
 import reconciliation_workflow  # noqa: E402
@@ -550,8 +553,9 @@ import review_merge_state_machine  # noqa: E402
 import native_mcp_preference  # noqa: E402
 
 
-# Fail-closed exact-issue-lock file (#204): written by gitea_lock_issue,
-# consumed by gitea_create_pr and scripts/worktree-start.
+# Keyed issue-lock storage (#443): per remote/org/repo/issue files under
+# GITEA_ISSUE_LOCK_DIR, bound to the current MCP session via a per-PID pointer.
+# Legacy global path retained only for test/doc references — do not seed manually.
 ISSUE_LOCK_FILE = "/tmp/gitea_issue_lock.json"
 WORK_LEASE_TTL_HOURS = 4
 AUTHOR_ISSUE_WORK_LEASE = "author_issue_work"
@@ -583,15 +587,59 @@ def _parse_work_lease_timestamp(value: str | None) -> datetime | None:
         return None
 
 
-def _load_existing_issue_lock() -> dict | None:
-    if not os.path.exists(ISSUE_LOCK_FILE):
-        return None
+def _load_existing_issue_lock(
+    *,
+    remote: str | None = None,
+    org: str | None = None,
+    repo: str | None = None,
+    issue_number: int | None = None,
+) -> dict | None:
+    if remote and org and repo and issue_number is not None:
+        return issue_lock_store.load_issue_lock(
+            remote=remote,
+            org=org,
+            repo=repo,
+            issue_number=issue_number,
+        )
+    return issue_lock_store.read_session_issue_lock()
+
+
+def _resolve_issue_lock_for_pr(
+    *,
+    remote: str,
+    org: str,
+    repo: str,
+    head: str,
+) -> dict:
+    lock_data = issue_lock_store.read_session_issue_lock()
+    if not lock_data:
+        lock_data = issue_lock_store.find_lock_for_branch(
+            remote=remote,
+            org=org,
+            repo=repo,
+            branch_name=head,
+        )
+    if not lock_data:
+        raise RuntimeError(
+            "Issue lock is missing (fail closed). Call gitea_lock_issue first."
+        )
+    return lock_data
+
+
+def _save_issue_lock(data: dict) -> str:
+    existing = issue_lock_store.load_issue_lock(
+        remote=str(data.get("remote") or ""),
+        org=str(data.get("org") or ""),
+        repo=str(data.get("repo") or ""),
+        issue_number=int(data.get("issue_number") or 0),
+    )
+    overwrite_block = issue_lock_store.assess_foreign_lock_overwrite(existing, data)
+    if overwrite_block:
+        raise RuntimeError(overwrite_block)
     try:
-        with open(ISSUE_LOCK_FILE, "r", encoding="utf-8") as f:
-            data = json.load(f)
-        return data if isinstance(data, dict) else None
-    except Exception:
-        return None
+        return issue_lock_store.bind_session_lock(data)
+    except Exception as e:
+        raise RuntimeError(f"Could not write issue lock file: {e}") from e
 
 
 def _work_lease_claimant(host: str | None) -> dict:
@@ -794,6 +842,19 @@ def _enforce_locked_issue_duplicate_recheck(
     return None
 
 
+def _branch_entry_commit_sha(branch: dict | str) -> str | None:
+    """Best-effort head SHA for a Gitea branch entry (None when absent)."""
+    if not isinstance(branch, dict):
+        return None
+    commit = branch.get("commit")
+    if isinstance(commit, dict):
+        sha = commit.get("id") or commit.get("sha")
+        if sha:
+            return str(sha)
+    sha = branch.get("commit_sha")
+    return str(sha) if sha else None
+
+
 def _reveal_endpoints() -> bool:
     """Admin/debug opt-in (#120): include endpoint URLs and token source
     names in tool output. Off by default so normal LLM-facing responses
@@ -1241,8 +1302,9 @@ def gitea_lock_issue(
     resolved_worktree = issue_lock_worktree.resolve_author_worktree_path(
         worktree_path, PROJECT_ROOT
     )
-    active_lease_block = _active_work_lease_block(
-        _load_existing_issue_lock(),
+    h, o, r = _resolve(remote, host, org, repo)
+    active_lease_block = issue_lock_store.assess_same_issue_lease_conflict(
+        _load_existing_issue_lock(remote=remote, org=o, repo=r, issue_number=issue_number),
         issue_number=issue_number,
         branch_name=branch_name,
         worktree_path=resolved_worktree,
@@ -1266,7 +1328,6 @@ def gitea_lock_issue(
             issue_lock_worktree.format_issue_lock_worktree_error(lock_assessment)
         )
 
-    h, o, r = _resolve(remote, host, org, repo)
     auth = _auth(h)
     duplicate_gate = _assess_issue_duplicate_gate(
         issue_number,
@@ -1282,6 +1343,30 @@ def gitea_lock_issue(
             f"duplicate work gate blocked issue #{issue_number} (fail closed)"
         ]))
 
+    branch_url = f"{repo_api_url(h, o, r)}/branches"
+    try:
+        branches = api_get_all(branch_url, auth)
+    except Exception as e:
+        raise RuntimeError(f"Could not list branches to verify issue lock: {e}")
+    existing_branch_entries = [
+        {
+            "name": _branch_entry_name(branch),
+            "commit_sha": _branch_entry_commit_sha(branch),
+        }
+        for branch in branches
+    ]
+    adoption = issue_lock_adoption.assess_own_branch_adoption(
+        issue_number=issue_number,
+        requested_branch=branch_name,
+        existing_branches=existing_branch_entries,
+    )
+    if adoption["block"]:
+        competing = ", ".join(adoption["competing_branches"])
+        raise ValueError(
+            f"Issue #{issue_number} already has matching branch '{competing}' "
+            "that is not the requested branch (fail closed)"
+        )
+
     work_lease = _build_author_issue_work_lease(
         issue_number=issue_number,
         branch_name=branch_name,
@@ -1302,11 +1387,7 @@ def gitea_lock_issue(
         ),
     }
 
-    try:
-        with open(ISSUE_LOCK_FILE, "w", encoding="utf-8") as f:
-            json.dump(data, f)
-    except Exception as e:
-        raise RuntimeError(f"Could not write issue lock file: {e}")
+    lock_file_path = _save_issue_lock(data)
 
     agent_artifacts = agent_temp_artifacts.find_agent_temp_artifacts_from_porcelain(
         git_state.get("porcelain_status") or ""
@@ -1321,7 +1402,22 @@ def gitea_lock_issue(
         "branch_name": branch_name,
         "worktree_path": resolved_worktree,
         "work_lease": work_lease,
+        "lock_file_path": lock_file_path,
     }
+    if adoption["adopt"]:
+        result["adoption"] = issue_lock_adoption.build_adoption_proof(
+            issue_number=issue_number,
+            branch_name=branch_name,
+            assessment=adoption,
+            open_pr_checked=True,
+            competing_lock_checked=True,
+            lock_file_path=lock_file_path,
+            lock_file_status="written",
+        )
+        result["message"] = (
+            f"Adopted existing branch '{branch_name}' and locked issue "
+            f"#{issue_number} for recovery (fail-closed check complete)."
+        )
     if agent_artifacts:
         result["warnings"] = [
             "Agent temp artifacts at repo root (delete before implementation): "
@@ -1413,15 +1509,8 @@ def gitea_create_pr(
     verify_preflight_purity(remote, worktree_path=worktree_path)
     h, o, r = _resolve(remote, host, org, repo)
 
-    # ── Issue Lock Validation (Issue #194 / #196) ──
-    if not os.path.exists(ISSUE_LOCK_FILE):
-        raise RuntimeError("Issue lock is missing (fail closed). Call gitea_lock_issue first.")
-
-    try:
-        with open(ISSUE_LOCK_FILE, "r", encoding="utf-8") as f:
-            lock_data = json.load(f)
-    except Exception as e:
-        raise RuntimeError(f"Could not read issue lock file: {e} (fail closed)")
+    # ── Issue Lock Validation (Issue #194 / #196 / #443) ──
+    lock_data = _resolve_issue_lock_for_pr(remote=remote, org=o, repo=r, head=head)
 
     lock_provenance_check = issue_lock_provenance.assess_lock_file_for_create_pr(
         lock_data
@@ -2016,6 +2105,7 @@ def init_review_decision_lock(remote: str | None, task: str | None):
         (os.environ.get(SESSION_PROFILE_LOCK_ENV) or "").strip()
         or profile_name
     )
+    reviewer_pr_lease.clear_session_lease()
     _save_review_decision_lock({
         "task": task,
         "remote": remote,
@@ -2458,6 +2548,20 @@ def _evaluate_pr_review_submission(
             result["permission_report"] = elig["permission_report"]
         return result
 
+    if live:
+        reasons.extend(_reviewer_pr_lease_gate(
+            pr_number=pr_number,
+            remote=remote,
+            host=host,
+            org=org,
+            repo=repo,
+            mutation=action,
+            live_head_sha=result.get("head_sha"),
+            pinned_head_sha=expected_head_sha,
+        ))
+        if reasons:
+            return result
+
     auth_user = result["authenticated_user"]
     pr_author = result["pr_author"]
     if action == "approve" and auth_user and pr_author and auth_user == pr_author:
@@ -2940,13 +3044,7 @@ def _prepare_commit_payload_files(files: list[dict]) -> tuple[list[dict], list[d
     processed_files = []
     source_proofs = []
 
-    lock_data = {}
-    if os.path.exists(ISSUE_LOCK_FILE):
-        try:
-            with open(ISSUE_LOCK_FILE, "r", encoding="utf-8") as f:
-                lock_data = json.load(f)
-        except Exception:
-            pass
+    lock_data = issue_lock_store.read_session_issue_lock() or {}
 
     locked_worktree = lock_data.get("worktree_path")
     if locked_worktree:
@@ -3257,6 +3355,19 @@ def gitea_merge_pr(
             result["permission_report"] = elig["permission_report"]
         return result
 
+    reasons.extend(_reviewer_pr_lease_gate(
+        pr_number=pr_number,
+        remote=remote,
+        host=host,
+        org=org,
+        repo=repo,
+        mutation="merge",
+        live_head_sha=result.get("head_sha"),
+        pinned_head_sha=expected_head_sha,
+    ))
+    if reasons:
+        return result
+
     # Gate 4 — head SHA must match if the caller pinned a reviewed SHA.
     actual_sha = result["head_sha"]
     if expected_head_sha and actual_sha and expected_head_sha != actual_sha:
@@ -4556,6 +4667,261 @@ def _namespace_mutation_block(mutation_task: str, **extra_fields) -> dict | None
     return blocked
 
 
+def _fetch_pr_comments(
+    pr_number: int,
+    *,
+    remote: str,
+    host: str | None,
+    org: str | None,
+    repo: str | None,
+) -> list[dict]:
+    h, o, r = _resolve(remote, host, org, repo)
+    auth = _auth(h)
+    api = f"{repo_api_url(h, o, r)}/issues/{pr_number}/comments"
+    return api_request("GET", api, auth) or []
+
+
+def _reviewer_pr_lease_gate(
+    *,
+    pr_number: int,
+    remote: str,
+    host: str | None,
+    org: str | None,
+    repo: str | None,
+    mutation: str,
+    live_head_sha: str | None,
+    pinned_head_sha: str | None,
+) -> list[str]:
+    """Return block reasons when the session lacks an owned PR reviewer lease."""
+    session = reviewer_pr_lease.get_session_lease()
+    session_id = (session or {}).get("session_id")
+    identity = _authenticated_username(remote) or ""
+    try:
+        comments = _fetch_pr_comments(
+            pr_number, remote=remote, host=host, org=org, repo=repo)
+    except Exception as exc:
+        return [f"cannot fetch PR comments for lease gate: {_redact(str(exc))}"]
+    assessment = reviewer_pr_lease.assess_mutation_lease_gate(
+        pr_number=pr_number,
+        comments=comments,
+        reviewer_identity=identity,
+        session_id=session_id,
+        mutation=mutation,
+        live_head_sha=live_head_sha,
+        pinned_head_sha=pinned_head_sha,
+    )
+    return list(assessment.get("reasons") or []) if assessment.get("block") else []
+
+
+@mcp.tool()
+def gitea_acquire_reviewer_pr_lease(
+    pr_number: int,
+    worktree: str,
+    candidate_head: str | None = None,
+    target_branch: str = "master",
+    target_branch_sha: str | None = None,
+    issue_number: int | None = None,
+    session_id: str | None = None,
+    remote: str = "dadeschools",
+    host: str | None = None,
+    org: str | None = None,
+    repo: str | None = None,
+) -> dict:
+    """Acquire a per-PR reviewer lease before review/merge mutations (#407)."""
+    read_block = _profile_operation_gate("gitea.read")
+    if read_block:
+        return {
+            "success": False,
+            "acquired": False,
+            "reasons": read_block,
+            "permission_report": _permission_block_report("gitea.read"),
+        }
+    comment_block = _profile_operation_gate("gitea.pr.comment")
+    if comment_block:
+        return {
+            "success": False,
+            "acquired": False,
+            "reasons": comment_block,
+            "permission_report": _permission_block_report("gitea.pr.comment"),
+        }
+
+    verify_preflight_purity(remote)
+    h, o, r = _resolve(remote, host, org, repo)
+    auth = _auth(h)
+    profile = get_profile()
+    identity = _authenticated_username(remote) or profile.get("username") or ""
+    sid = (session_id or "").strip() or reviewer_pr_lease.new_session_id()
+    repo_label = f"{o}/{r}"
+
+    comments = _fetch_pr_comments(
+        pr_number, remote=remote, host=host, org=org, repo=repo)
+    assessment = reviewer_pr_lease.assess_acquire_lease(
+        comments,
+        pr_number=pr_number,
+        reviewer_identity=identity,
+        profile=profile.get("profile_name") or "unknown",
+        session_id=sid,
+        repo=repo_label,
+        issue_number=issue_number,
+        worktree=worktree,
+        candidate_head=candidate_head,
+        target_branch=target_branch,
+        target_branch_sha=target_branch_sha,
+    )
+    if not assessment.get("acquire_allowed"):
+        return {
+            "success": False,
+            "acquired": False,
+            "reasons": assessment.get("reasons") or [],
+            "existing_lease": assessment.get("existing_lease"),
+        }
+
+    body = assessment["lease_body"]
+    comment_url = f"{repo_api_url(h, o, r)}/issues/{pr_number}/comments"
+    with _audited(
+        "comment_pr",
+        host=h,
+        remote=remote,
+        org=o,
+        repo=r,
+        pr_number=pr_number,
+        request_metadata={"source": "acquire_reviewer_pr_lease"},
+    ):
+        posted = api_request("POST", comment_url, auth, {"body": body})
+
+    session_lease = reviewer_pr_lease.record_session_lease({
+        "pr_number": pr_number,
+        "issue_number": issue_number,
+        "session_id": sid,
+        "reviewer_identity": identity,
+        "profile": profile.get("profile_name"),
+        "worktree": worktree,
+        "phase": "claimed",
+        "candidate_head": candidate_head,
+        "target_branch": target_branch,
+        "target_branch_sha": target_branch_sha,
+        "repo": repo_label,
+        "comment_id": posted.get("id"),
+    })
+    return {
+        "success": True,
+        "acquired": True,
+        "pr_number": pr_number,
+        "session_id": sid,
+        "comment_id": posted.get("id"),
+        "session_lease": session_lease,
+        "reasons": [],
+    }
+
+
+@mcp.tool()
+def gitea_heartbeat_reviewer_pr_lease(
+    pr_number: int,
+    phase: str,
+    worktree: str | None = None,
+    candidate_head: str | None = None,
+    target_branch_sha: str | None = None,
+    remote: str = "dadeschools",
+    host: str | None = None,
+    org: str | None = None,
+    repo: str | None = None,
+) -> dict:
+    """Post a reviewer lease heartbeat / phase update on the PR thread (#407)."""
+    comment_block = _profile_operation_gate("gitea.pr.comment")
+    if comment_block:
+        return {
+            "success": False,
+            "posted": False,
+            "reasons": comment_block,
+            "permission_report": _permission_block_report("gitea.pr.comment"),
+        }
+    session = reviewer_pr_lease.get_session_lease()
+    if not session or session.get("pr_number") != pr_number:
+        return {
+            "success": False,
+            "posted": False,
+            "reasons": [
+                f"no in-session lease for PR #{pr_number}; acquire first "
+                "(fail closed)"
+            ],
+        }
+
+    verify_preflight_purity(remote)
+    h, o, r = _resolve(remote, host, org, repo)
+    auth = _auth(h)
+    body = reviewer_pr_lease.format_lease_body(
+        repo=f"{o}/{r}",
+        pr_number=pr_number,
+        issue_number=session.get("issue_number"),
+        reviewer_identity=session.get("reviewer_identity") or "",
+        profile=session.get("profile") or "unknown",
+        session_id=session.get("session_id") or reviewer_pr_lease.new_session_id(),
+        worktree=worktree or session.get("worktree") or "",
+        phase=phase,
+        candidate_head=candidate_head or session.get("candidate_head"),
+        target_branch=session.get("target_branch") or "master",
+        target_branch_sha=target_branch_sha or session.get("target_branch_sha"),
+    )
+    comment_url = f"{repo_api_url(h, o, r)}/issues/{pr_number}/comments"
+    with _audited(
+        "comment_pr",
+        host=h,
+        remote=remote,
+        org=o,
+        repo=r,
+        pr_number=pr_number,
+        request_metadata={"source": "heartbeat_reviewer_pr_lease", "phase": phase},
+    ):
+        posted = api_request("POST", comment_url, auth, {"body": body})
+
+    updated = reviewer_pr_lease.record_session_lease({
+        **session,
+        "phase": phase,
+        "worktree": worktree or session.get("worktree"),
+        "candidate_head": candidate_head or session.get("candidate_head"),
+        "target_branch_sha": target_branch_sha or session.get("target_branch_sha"),
+        "last_comment_id": posted.get("id"),
+    })
+    return {
+        "success": True,
+        "posted": True,
+        "pr_number": pr_number,
+        "phase": phase,
+        "comment_id": posted.get("id"),
+        "session_lease": updated,
+        "reasons": [],
+    }
+
+
+@mcp.tool()
+def gitea_assess_reviewer_pr_lease(
+    pr_number: int,
+    remote: str = "dadeschools",
+    host: str | None = None,
+    org: str | None = None,
+    repo: str | None = None,
+) -> dict:
+    """Read-only: assess active reviewer lease state for a PR (#407)."""
+    read_block = _profile_operation_gate("gitea.read")
+    if read_block:
+        return {
+            "success": False,
+            "reasons": read_block,
+            "permission_report": _permission_block_report("gitea.read"),
+        }
+    comments = _fetch_pr_comments(
+        pr_number, remote=remote, host=host, org=org, repo=repo)
+    active = reviewer_pr_lease.find_active_reviewer_lease(
+        comments, pr_number=pr_number)
+    return {
+        "success": True,
+        "pr_number": pr_number,
+        "active_lease": active,
+        "session_lease": reviewer_pr_lease.get_session_lease(),
+        "reasons": [],
+    }
+
+
 @mcp.tool()
 def gitea_list_issue_comments(
     issue_number: int,

issue_lock_adoption.py

@@ -0,0 +1,116 @@
+"""Own-branch lock adoption / recovery for ``gitea_lock_issue`` (#442 / #443).
+
+When an issue's own already-pushed branch exists, lock reacquisition must be
+allowed (adoption) instead of being treated as #400 duplicate competing work.
+This module isolates the pure decision so it can be unit-tested apart from the
+MCP server's live Gitea calls.
+
+Adoption is granted only for the issue's *exact* requested branch. Any other
+branch that merely contains the same ``issue-<n>`` marker is competing work and
+stays fail-closed. Open-PR, competing-live-lock, capability, and worktree
+safety checks are enforced by the caller before this decision is consulted;
+this module additionally records whether they passed for proof purposes.
+"""
+
+from __future__ import annotations
+
+ADOPT = "adopt_existing_branch"
+BLOCK_COMPETING = "block_competing_branch"
+NO_MATCH = "no_matching_branch"
+
+
+def _branch_name(entry) -> str:
+    if isinstance(entry, dict):
+        return str(entry.get("name") or "")
+    return str(entry or "")
+
+
+def _branch_sha(entry) -> str | None:
+    if isinstance(entry, dict):
+        sha = entry.get("commit_sha")
+        if sha:
+            return str(sha)
+    return None
+
+
+def assess_own_branch_adoption(
+    *,
+    issue_number: int,
+    requested_branch: str,
+    existing_branches,
+) -> dict:
+    """Decide whether an existing matching branch is adoptable."""
+    marker = f"issue-{issue_number}"
+    requested = (requested_branch or "").strip()
+
+    matches: list[tuple[str, str | None]] = []
+    for entry in existing_branches or []:
+        name = _branch_name(entry).strip()
+        if marker in name:
+            matches.append((name, _branch_sha(entry)))
+
+    competing = sorted({name for name, _ in matches if name != requested})
+    exact = [(name, sha) for name, sha in matches if name == requested]
+
+    if competing:
+        return {
+            "outcome": BLOCK_COMPETING,
+            "adopt": False,
+            "block": True,
+            "reason": (
+                f"issue #{issue_number} already has matching branch(es) "
+                f"{competing} that are not the requested branch "
+                f"'{requested}' (fail closed)"
+            ),
+            "matched_branch": None,
+            "matched_head_sha": None,
+            "competing_branches": competing,
+        }
+
+    if exact:
+        name, sha = exact[0]
+        return {
+            "outcome": ADOPT,
+            "adopt": True,
+            "block": False,
+            "reason": (
+                f"existing branch '{name}' is the exact requested branch for "
+                f"issue #{issue_number}; adopting it for lock recovery"
+            ),
+            "matched_branch": name,
+            "matched_head_sha": sha,
+            "competing_branches": [],
+        }
+
+    return {
+        "outcome": NO_MATCH,
+        "adopt": False,
+        "block": False,
+        "reason": f"no existing branch matches issue #{issue_number}",
+        "matched_branch": None,
+        "matched_head_sha": None,
+        "competing_branches": [],
+    }
+
+
+def build_adoption_proof(
+    *,
+    issue_number: int,
+    branch_name: str,
+    assessment: dict,
+    open_pr_checked: bool,
+    competing_lock_checked: bool,
+    lock_file_path: str,
+    lock_file_status: str,
+) -> dict:
+    """Assemble the proof block returned by ``gitea_lock_issue`` on adoption."""
+    return {
+        "issue_number": issue_number,
+        "branch_name": branch_name,
+        "branch_head_commit": assessment.get("matched_head_sha"),
+        "adoption_reason": assessment.get("reason"),
+        "no_existing_pr_proof": bool(open_pr_checked),
+        "no_competing_live_lock_proof": bool(competing_lock_checked),
+        "lock_file_path": lock_file_path,
+        "lock_file_status": lock_file_status,
+    }

issue_lock_store.py

@@ -0,0 +1,385 @@
+"""Keyed, persistent issue-lock storage (#443).
+
+Replaces the single global ``/tmp/gitea_issue_lock.json`` slot with per-issue
+lock files under ``GITEA_ISSUE_LOCK_DIR`` (default
+``~/.cache/gitea-tools/issue-locks``). Each MCP session binds its active lock
+via a per-process pointer file so concurrent repos/issues never clobber each
+other.
+"""
+
+from __future__ import annotations
+
+import json
+import os
+import re
+import tempfile
+from datetime import datetime, timedelta, timezone
+from typing import Any
+
+LOCK_DIR_ENV = "GITEA_ISSUE_LOCK_DIR"
+DEFAULT_LOCK_DIR = os.path.expanduser("~/.cache/gitea-tools/issue-locks")
+WORK_LEASE_TTL_HOURS = 4
+AUTHOR_ISSUE_WORK_LEASE = "author_issue_work"
+
+_SAFE_SEGMENT_RE = re.compile(r"[^A-Za-z0-9._+-]+")
+
+
+def default_lock_dir() -> str:
+    raw = (os.environ.get(LOCK_DIR_ENV) or DEFAULT_LOCK_DIR).strip()
+    return raw or DEFAULT_LOCK_DIR
+
+
+def _sanitize_segment(value: str) -> str:
+    text = (value or "").strip()
+    if not text:
+        return "_"
+    return _SAFE_SEGMENT_RE.sub("_", text)
+
+
+def lock_key(
+    *,
+    remote: str,
+    org: str,
+    repo: str,
+    issue_number: int,
+) -> str:
+    return "-".join(
+        _sanitize_segment(part)
+        for part in (remote, org, repo, str(issue_number))
+    )
+
+
+def lock_file_path(
+    *,
+    remote: str,
+    org: str,
+    repo: str,
+    issue_number: int,
+    lock_dir: str | None = None,
+) -> str:
+    root = (lock_dir or default_lock_dir()).strip()
+    return os.path.join(root, f"{lock_key(remote=remote, org=org, repo=repo, issue_number=issue_number)}.json")
+
+
+def session_pointer_path(lock_dir: str | None = None) -> str:
+    root = (lock_dir or default_lock_dir()).strip()
+    return os.path.join(root, f"session-{os.getpid()}.json")
+
+
+def _ensure_lock_dir(lock_dir: str | None = None) -> str:
+    root = (lock_dir or default_lock_dir()).strip()
+    os.makedirs(root, mode=0o700, exist_ok=True)
+    return root
+
+
+def read_lock_file(path: str) -> dict[str, Any] | None:
+    lock_path = (path or "").strip()
+    if not lock_path or not os.path.exists(lock_path):
+        return None
+    try:
+        with open(lock_path, encoding="utf-8") as handle:
+            data = json.load(handle)
+    except (OSError, json.JSONDecodeError):
+        return None
+    return data if isinstance(data, dict) else None
+
+
+def save_lock_file(path: str, data: dict[str, Any]) -> None:
+    lock_path = (path or "").strip()
+    if not lock_path:
+        raise ValueError("lock path is required (fail closed)")
+    parent = os.path.dirname(lock_path) or "."
+    os.makedirs(parent, mode=0o700, exist_ok=True)
+    payload = json.dumps(data, indent=2, sort_keys=True) + "\n"
+    fd, temp_path = tempfile.mkstemp(prefix=".lock-", suffix=".json", dir=parent)
+    try:
+        with os.fdopen(fd, "w", encoding="utf-8") as handle:
+            handle.write(payload)
+            handle.flush()
+            os.fsync(handle.fileno())
+        os.replace(temp_path, lock_path)
+    finally:
+        if os.path.exists(temp_path):
+            try:
+                os.remove(temp_path)
+            except OSError:
+                pass
+
+
+def bind_session_lock(lock_data: dict[str, Any], lock_dir: str | None = None) -> str:
+    """Persist a keyed lock and bind it to the current process session."""
+    remote = str(lock_data.get("remote") or "")
+    org = str(lock_data.get("org") or "")
+    repo = str(lock_data.get("repo") or "")
+    issue_number = int(lock_data.get("issue_number") or 0)
+    if not remote or not org or not repo or issue_number <= 0:
+        raise ValueError("lock record must include remote, org, repo, and issue_number")
+
+    root = _ensure_lock_dir(lock_dir)
+    path = lock_file_path(
+        remote=remote,
+        org=org,
+        repo=repo,
+        issue_number=issue_number,
+        lock_dir=root,
+    )
+    record = dict(lock_data)
+    record["lock_file_path"] = path
+    record["session_pid"] = os.getpid()
+    save_lock_file(path, record)
+
+    pointer = {
+        "pid": os.getpid(),
+        "lock_file_path": path,
+        "issue_number": issue_number,
+        "branch_name": record.get("branch_name"),
+        "remote": remote,
+        "org": org,
+        "repo": repo,
+    }
+    save_lock_file(session_pointer_path(root), pointer)
+    return path
+
+
+def read_session_issue_lock(lock_dir: str | None = None) -> dict[str, Any] | None:
+    root = (lock_dir or default_lock_dir()).strip()
+    pointer = read_lock_file(session_pointer_path(root))
+    if not pointer:
+        return None
+    lock_path = str(pointer.get("lock_file_path") or "").strip()
+    if not lock_path:
+        return None
+    return read_lock_file(lock_path)
+
+
+def load_issue_lock(
+    *,
+    remote: str,
+    org: str,
+    repo: str,
+    issue_number: int,
+    lock_dir: str | None = None,
+) -> dict[str, Any] | None:
+    return read_lock_file(
+        lock_file_path(
+            remote=remote,
+            org=org,
+            repo=repo,
+            issue_number=issue_number,
+            lock_dir=lock_dir,
+        )
+    )
+
+
+def iter_lock_files(lock_dir: str | None = None) -> list[str]:
+    root = (lock_dir or default_lock_dir()).strip()
+    if not os.path.isdir(root):
+        return []
+    paths: list[str] = []
+    for name in os.listdir(root):
+        if not name.endswith(".json") or name.startswith("session-"):
+            continue
+        paths.append(os.path.join(root, name))
+    return sorted(paths)
+
+
+def find_lock_for_branch(
+    *,
+    remote: str,
+    org: str,
+    repo: str,
+    branch_name: str,
+    lock_dir: str | None = None,
+) -> dict[str, Any] | None:
+    target = (branch_name or "").strip()
+    if not target:
+        return None
+    for path in iter_lock_files(lock_dir):
+        lock = read_lock_file(path)
+        if not lock:
+            continue
+        if (
+            str(lock.get("remote") or "") == remote
+            and str(lock.get("org") or "") == org
+            and str(lock.get("repo") or "") == repo
+            and str(lock.get("branch_name") or "").strip() == target
+        ):
+            lock = dict(lock)
+            lock.setdefault("lock_file_path", path)
+            return lock
+    return None
+
+
+def _lease_now(now: datetime | None = None) -> datetime:
+    return now or datetime.now(timezone.utc)
+
+
+def _parse_lease_timestamp(value: str | None) -> datetime | None:
+    text = (value or "").strip()
+    if not text:
+        return None
+    try:
+        return datetime.fromisoformat(text.replace("Z", "+00:00")).astimezone(timezone.utc)
+    except ValueError:
+        return None
+
+
+def lease_expires_at(lock: dict[str, Any] | None) -> datetime | None:
+    if not lock:
+        return None
+    lease = lock.get("work_lease")
+    if not isinstance(lease, dict):
+        return None
+    return _parse_lease_timestamp(lease.get("expires_at"))
+
+
+def is_lease_expired(lock: dict[str, Any] | None, *, now: datetime | None = None) -> bool:
+    expires = lease_expires_at(lock)
+    if expires is None:
+        return False
+    return expires <= _lease_now(now)
+
+
+def is_lease_live(lock: dict[str, Any] | None, *, now: datetime | None = None) -> bool:
+    if not lock:
+        return False
+    lease = lock.get("work_lease")
+    if not isinstance(lease, dict):
+        return True
+    expires = _parse_lease_timestamp(lease.get("expires_at"))
+    if expires is None:
+        return True
+    return expires > _lease_now(now)
+
+
+def _same_realpath(left: str | None, right: str | None) -> bool:
+    if not left or not right:
+        return False
+    try:
+        return os.path.realpath(left) == os.path.realpath(right)
+    except OSError:
+        return left == right
+
+
+def assess_same_issue_lease_conflict(
+    existing_lock: dict[str, Any] | None,
+    *,
+    issue_number: int,
+    branch_name: str,
+    worktree_path: str,
+    operation_type: str = AUTHOR_ISSUE_WORK_LEASE,
+    now: datetime | None = None,
+) -> str | None:
+    """Return a fail-closed error when a competing live lease blocks acquisition."""
+    if not existing_lock:
+        return None
+
+    existing_issue = existing_lock.get("issue_number")
+    lease = existing_lock.get("work_lease")
+    existing_operation = (
+        lease.get("operation_type")
+        if isinstance(lease, dict)
+        else AUTHOR_ISSUE_WORK_LEASE
+    )
+    if existing_issue != issue_number or existing_operation != operation_type:
+        return None
+
+    existing_branch = existing_lock.get("branch_name")
+    existing_worktree = existing_lock.get("worktree_path")
+    same_owner = (
+        existing_branch == branch_name
+        and _same_realpath(str(existing_worktree or ""), worktree_path)
+    )
+    if is_lease_expired(existing_lock, now=now):
+        return (
+            f"Issue #{issue_number} has an expired {operation_type} lease on "
+            f"branch '{existing_branch}' from worktree '{existing_worktree}'. "
+            "Recovery review is required before takeover (fail closed)"
+        )
+    if same_owner:
+        return None
+    return (
+        f"Issue #{issue_number} already has an active {operation_type} lease on "
+        f"branch '{existing_branch}' from worktree '{existing_worktree}' "
+        "(fail closed)"
+    )
+
+
+def assess_foreign_lock_overwrite(
+    existing_lock: dict[str, Any] | None,
+    incoming_lock: dict[str, Any],
+    *,
+    now: datetime | None = None,
+) -> str | None:
+    """Block writes that would clobber an unrelated live lease on the same key."""
+    if not existing_lock:
+        return None
+
+    same_issue = existing_lock.get("issue_number") == incoming_lock.get("issue_number")
+    same_branch = existing_lock.get("branch_name") == incoming_lock.get("branch_name")
+    same_worktree = _same_realpath(
+        str(existing_lock.get("worktree_path") or ""),
+        str(incoming_lock.get("worktree_path") or ""),
+    )
+    if same_issue and same_branch and same_worktree:
+        return None
+    if not is_lease_live(existing_lock, now=now):
+        return None
+    return (
+        "Refusing to overwrite a live foreign issue lock "
+        f"(issue #{existing_lock.get('issue_number')}, "
+        f"branch '{existing_lock.get('branch_name')}', "
+        f"worktree '{existing_lock.get('worktree_path')}') (fail closed)"
+    )
+
+
+def find_live_lock_for_branch(
+    branch_name: str,
+    lock_dir: str | None = None,
+) -> dict[str, Any] | None:
+    target = (branch_name or "").strip()
+    if not target:
+        return None
+    for path in iter_lock_files(lock_dir):
+        lock = read_lock_file(path)
+        if not lock:
+            continue
+        if str(lock.get("branch_name") or "").strip() != target:
+            continue
+        if not is_lease_live(lock):
+            continue
+        record = dict(lock)
+        record.setdefault("lock_file_path", path)
+        return record
+    return None
+
+
+def resolve_locked_branch_for_session(
+    branch_name: str | None = None,
+    lock_dir: str | None = None,
+) -> str:
+    if branch_name:
+        lock = find_live_lock_for_branch(branch_name, lock_dir)
+        if lock:
+            return str(lock.get("branch_name") or "")
+    lock = read_session_issue_lock(lock_dir)
+    return str((lock or {}).get("branch_name") or "")
+
+
+def has_active_issue_lock(
+    branch: str,
+    *,
+    lock_dir: str | None = None,
+) -> bool:
+    target = (branch or "").strip()
+    if not target:
+        return False
+    for path in iter_lock_files(lock_dir):
+        lock = read_lock_file(path)
+        if not lock:
+            continue
+        if str(lock.get("branch_name") or "").strip() != target:
+            continue
+        if is_lease_live(lock):
+            return True
+    return False

merged_cleanup_reconcile.py

@@ -13,9 +13,9 @@ import subprocess
 from typing import Any
 
 from reviewer_worktree import parse_dirty_tracked_files
+import issue_lock_store
 
 PROTECTED_BRANCHES = frozenset({"master", "main", "dev"})
-ISSUE_LOCK_FILE = os.environ.get("GITEA_ISSUE_LOCK_FILE", "/tmp/gitea_issue_lock.json")
 CLOSES_FIXES_RE = re.compile(r"\b(?:closes|fixes)\s+#(\d+)\b", re.IGNORECASE)
 
 
@@ -37,22 +37,18 @@ def resolve_worktree_path(project_root: str, branch: str) -> str:
 
 
 def read_issue_lock(path: str | None = None) -> dict[str, Any] | None:
-    lock_path = (path or ISSUE_LOCK_FILE).strip()
-    if not lock_path or not os.path.exists(lock_path):
-        return None
-    try:
-        with open(lock_path, encoding="utf-8") as handle:
-            data = json.load(handle)
-    except (OSError, json.JSONDecodeError):
-        return None
-    return data if isinstance(data, dict) else None
+    if path:
+        return issue_lock_store.read_lock_file(path.strip())
+    return issue_lock_store.read_session_issue_lock()
 
 
 def has_active_issue_lock(branch: str, lock_path: str | None = None) -> bool:
-    lock = read_issue_lock(lock_path)
-    if not lock:
-        return False
-    return (lock.get("branch_name") or "").strip() == (branch or "").strip()
+    if lock_path:
+        lock = issue_lock_store.read_lock_file(lock_path.strip())
+        if not lock:
+            return False
+        return (lock.get("branch_name") or "").strip() == (branch or "").strip()
+    return issue_lock_store.has_active_issue_lock(branch)
 
 
 def collect_open_pr_heads(open_prs: list[dict[str, Any]]) -> set[str]:

reviewer_pr_lease.py

@@ -0,0 +1,382 @@
+"""Per-PR reviewer leases for safe parallel review sessions (#407)."""
+
+from __future__ import annotations
+
+import os
+import re
+import uuid
+from datetime import datetime, timedelta, timezone
+from typing import Any
+
+MARKER = "<!-- mcp-review-lease:v1 -->"
+
+_FIELD_RE = re.compile(
+    r"^\s*([a-z_]+)\s*:\s*(.+?)\s*$",
+    re.IGNORECASE | re.MULTILINE,
+)
+_FULL_SHA = re.compile(r"^[0-9a-f]{40}$", re.IGNORECASE)
+
+_TERMINAL_PHASES = frozenset({"done", "released", "blocked"})
+_ACTIVE_PHASES = frozenset({
+    "claimed",
+    "validating",
+    "approved",
+    "request-changes",
+    "merging",
+})
+
+DEFAULT_LEASE_TTL_MINUTES = 120
+STALE_WARNING_MINUTES = 30
+RECLAIMABLE_MINUTES = 60
+
+_SESSION_LEASE: dict[str, Any] | None = None
+
+
+def _parse_timestamp(value: str | None) -> datetime | None:
+    if not value:
+        return None
+    text = value.strip()
+    if text.endswith("Z"):
+        text = text[:-1] + "+00:00"
+    try:
+        parsed = datetime.fromisoformat(text)
+    except ValueError:
+        return None
+    if parsed.tzinfo is None:
+        return parsed.replace(tzinfo=timezone.utc)
+    return parsed.astimezone(timezone.utc)
+
+
+def _normalize_sha(value: str | None) -> str | None:
+    text = (value or "").strip().lower()
+    return text if text and _FULL_SHA.match(text) else None
+
+
+def _parse_pr_ref(value: str | None) -> int | None:
+    digits = re.sub(r"[^\d]", "", value or "")
+    return int(digits) if digits.isdigit() else None
+
+
+def new_session_id() -> str:
+    return f"{os.getpid()}-{uuid.uuid4().hex[:12]}"
+
+
+def format_lease_body(
+    *,
+    repo: str,
+    pr_number: int,
+    issue_number: int | None,
+    reviewer_identity: str,
+    profile: str,
+    session_id: str,
+    worktree: str,
+    phase: str,
+    candidate_head: str | None,
+    target_branch: str,
+    target_branch_sha: str | None,
+    last_activity: datetime | None = None,
+    expires_at: datetime | None = None,
+    blocker: str = "none",
+) -> str:
+    now = last_activity or datetime.now(timezone.utc)
+    expires = expires_at or (now + timedelta(minutes=DEFAULT_LEASE_TTL_MINUTES))
+    last_text = now.astimezone(timezone.utc).replace(microsecond=0).isoformat().replace(
+        "+00:00", "Z"
+    )
+    expires_text = expires.astimezone(timezone.utc).replace(microsecond=0).isoformat().replace(
+        "+00:00", "Z"
+    )
+    issue_text = f"#{issue_number}" if issue_number else "none"
+    lines = [
+        MARKER,
+        f"repo: {repo}",
+        f"pr: #{pr_number}",
+        f"issue: {issue_text}",
+        f"reviewer_identity: {reviewer_identity}",
+        f"profile: {profile}",
+        f"session_id: {session_id}",
+        f"worktree: {worktree}",
+        f"phase: {phase}",
+        f"candidate_head: {candidate_head or 'none'}",
+        f"target_branch: {target_branch}",
+        f"target_branch_sha: {target_branch_sha or 'none'}",
+        f"last_activity: {last_text}",
+        f"expires_at: {expires_text}",
+        f"blocker: {blocker}",
+    ]
+    return "\n".join(lines)
+
+
+def parse_lease_comment(body: str) -> dict[str, Any] | None:
+    text = body or ""
+    if MARKER not in text:
+        return None
+    fields: dict[str, str] = {}
+    for match in _FIELD_RE.finditer(text):
+        fields[match.group(1).strip().lower()] = match.group(2).strip()
+    if not fields:
+        return None
+    return {
+        "repo": fields.get("repo"),
+        "pr_number": _parse_pr_ref(fields.get("pr")),
+        "issue_number": _parse_pr_ref(fields.get("issue")),
+        "reviewer_identity": fields.get("reviewer_identity"),
+        "profile": fields.get("profile"),
+        "session_id": fields.get("session_id"),
+        "worktree": fields.get("worktree"),
+        "phase": (fields.get("phase") or "").strip().lower() or None,
+        "candidate_head": _normalize_sha(fields.get("candidate_head")),
+        "target_branch": fields.get("target_branch"),
+        "target_branch_sha": _normalize_sha(fields.get("target_branch_sha")),
+        "last_activity": fields.get("last_activity"),
+        "expires_at": fields.get("expires_at"),
+        "blocker": fields.get("blocker"),
+        "raw_fields": fields,
+    }
+
+
+def _lease_entries(comments: list[dict], *, pr_number: int) -> list[dict]:
+    entries: list[dict] = []
+    for comment in comments or []:
+        parsed = parse_lease_comment(comment.get("body") or "")
+        if not parsed:
+            continue
+        if parsed.get("pr_number") not in (None, pr_number):
+            continue
+        entries.append({
+            **parsed,
+            "comment_id": comment.get("id"),
+            "author": (comment.get("user") or {}).get("login") or comment.get("author"),
+            "created_at": comment.get("created_at"),
+            "updated_at": comment.get("updated_at"),
+        })
+    return entries
+
+
+def _lease_expired(lease: dict, *, now: datetime) -> bool:
+    expires_at = _parse_timestamp(lease.get("expires_at"))
+    return bool(expires_at and expires_at <= now)
+
+
+def _minutes_since_activity(lease: dict, *, now: datetime) -> float | None:
+    last = _parse_timestamp(lease.get("last_activity"))
+    if not last:
+        return None
+    return (now - last).total_seconds() / 60.0
+
+
+def classify_lease_freshness(lease: dict, *, now: datetime | None = None) -> str:
+    """Return active, stale_warning, reclaimable, expired, or terminal."""
+    now = now or datetime.now(timezone.utc)
+    phase = (lease.get("phase") or "").strip().lower()
+    if phase in _TERMINAL_PHASES:
+        return "terminal"
+    if _lease_expired(lease, now=now):
+        return "expired"
+    minutes = _minutes_since_activity(lease, now=now)
+    if minutes is None:
+        return "active"
+    if minutes >= RECLAIMABLE_MINUTES:
+        return "reclaimable"
+    if minutes >= STALE_WARNING_MINUTES:
+        return "stale_warning"
+    return "active"
+
+
+def find_active_reviewer_lease(
+    comments: list[dict],
+    *,
+    pr_number: int,
+    now: datetime | None = None,
+) -> dict[str, Any] | None:
+    """Newest non-terminal, unexpired lease for *pr_number*."""
+    now = now or datetime.now(timezone.utc)
+    for lease in reversed(_lease_entries(comments, pr_number=pr_number)):
+        phase = (lease.get("phase") or "").strip().lower()
+        if phase in _TERMINAL_PHASES:
+            continue
+        if _lease_expired(lease, now=now):
+            continue
+        if phase in _ACTIVE_PHASES or phase:
+            lease = dict(lease)
+            lease["freshness"] = classify_lease_freshness(lease, now=now)
+            return lease
+    return None
+
+
+def assess_acquire_lease(
+    comments: list[dict],
+    *,
+    pr_number: int,
+    reviewer_identity: str,
+    profile: str,
+    session_id: str,
+    repo: str,
+    issue_number: int | None,
+    worktree: str,
+    candidate_head: str | None,
+    target_branch: str,
+    target_branch_sha: str | None,
+    now: datetime | None = None,
+) -> dict[str, Any]:
+    """Fail closed when another session holds an active lease."""
+    now = now or datetime.now(timezone.utc)
+    reasons: list[str] = []
+    existing = find_active_reviewer_lease(comments, pr_number=pr_number, now=now)
+    if existing:
+        owner_session = (existing.get("session_id") or "").strip()
+        freshness = existing.get("freshness") or classify_lease_freshness(existing, now=now)
+        if owner_session and owner_session != session_id and freshness in {
+            "active", "stale_warning"
+        }:
+            reasons.append(
+                f"PR #{pr_number} already has active reviewer lease "
+                f"(session_id={owner_session}, phase={existing.get('phase')})"
+            )
+        elif owner_session and owner_session != session_id and freshness == "reclaimable":
+            reasons.append(
+                f"PR #{pr_number} lease is reclaimable but still held by "
+                f"session_id={owner_session}; explicit reclaim not implemented "
+                "(fail closed)"
+            )
+
+    if not (reviewer_identity or "").strip():
+        reasons.append("reviewer identity required for lease acquisition")
+    if not (session_id or "").strip():
+        reasons.append("session_id required for lease acquisition")
+    if not (worktree or "").strip():
+        reasons.append("worktree path required for lease acquisition")
+
+    allowed = not reasons
+    body = None
+    if allowed:
+        body = format_lease_body(
+            repo=repo,
+            pr_number=pr_number,
+            issue_number=issue_number,
+            reviewer_identity=reviewer_identity,
+            profile=profile,
+            session_id=session_id,
+            worktree=worktree,
+            phase="claimed",
+            candidate_head=candidate_head,
+            target_branch=target_branch,
+            target_branch_sha=target_branch_sha,
+            last_activity=now,
+        )
+    return {
+        "acquire_allowed": allowed,
+        "reasons": reasons,
+        "existing_lease": existing,
+        "lease_body": body,
+        "session_id": session_id,
+    }
+
+
+def record_session_lease(lease: dict[str, Any]) -> dict[str, Any]:
+    global _SESSION_LEASE
+    _SESSION_LEASE = dict(lease)
+    return dict(_SESSION_LEASE)
+
+
+def clear_session_lease() -> None:
+    global _SESSION_LEASE
+    _SESSION_LEASE = None
+
+
+def get_session_lease() -> dict[str, Any] | None:
+    return dict(_SESSION_LEASE) if _SESSION_LEASE else None
+
+
+def assess_mutation_lease_gate(
+    *,
+    pr_number: int,
+    comments: list[dict],
+    reviewer_identity: str,
+    session_id: str | None,
+    mutation: str,
+    live_head_sha: str | None,
+    pinned_head_sha: str | None,
+    now: datetime | None = None,
+) -> dict[str, Any]:
+    """Reviewer mutations require an owned, current PR lease."""
+    now = now or datetime.now(timezone.utc)
+    reasons: list[str] = []
+    session = get_session_lease()
+    active = find_active_reviewer_lease(comments, pr_number=pr_number, now=now)
+
+    if not session:
+        reasons.append(
+            f"no in-session reviewer lease recorded; acquire via "
+            f"gitea_acquire_reviewer_pr_lease before {mutation}"
+        )
+    elif session.get("pr_number") != pr_number:
+        reasons.append(
+            f"session lease is for PR #{session.get('pr_number')}, not #{pr_number}"
+        )
+    elif (session.get("session_id") or "") != (session_id or session.get("session_id")):
+        reasons.append("session lease session_id mismatch (fail closed)")
+
+    if active:
+        owner = (active.get("session_id") or "").strip()
+        if owner and session_id and owner != session_id:
+            reasons.append(
+                f"active PR lease owned by session_id={owner}; current session "
+                f"cannot {mutation}"
+            )
+        pinned = _normalize_sha(pinned_head_sha)
+        live = _normalize_sha(live_head_sha)
+        lease_head = active.get("candidate_head")
+        if pinned and live and pinned != live:
+            reasons.append(
+                "PR head changed during lease; stop and re-validate before "
+                f"reviewer {mutation}"
+            )
+        if lease_head and live and lease_head != live:
+            reasons.append(
+                "live PR head differs from lease candidate_head; refresh lease "
+                f"before {mutation}"
+            )
+        freshness = active.get("freshness") or classify_lease_freshness(active, now=now)
+        if freshness in {"expired", "reclaimable"}:
+            reasons.append(f"reviewer lease freshness is '{freshness}' (fail closed)")
+    else:
+        reasons.append(f"no active reviewer lease found on PR #{pr_number}")
+
+    allowed = not reasons
+    return {
+        "mutation_allowed": allowed,
+        "block": not allowed,
+        "reasons": reasons,
+        "active_lease": active,
+        "session_lease": session,
+    }
+
+
+def assess_lease_inventory(
+    comments_by_pr: dict[int, list[dict]],
+    *,
+    now: datetime | None = None,
+) -> dict[str, Any]:
+    """Summarize lease states across PR comment threads."""
+    now = now or datetime.now(timezone.utc)
+    active: list[dict] = []
+    stale: list[dict] = []
+    reclaimable: list[dict] = []
+    for pr_number, comments in (comments_by_pr or {}).items():
+        lease = find_active_reviewer_lease(comments, pr_number=pr_number, now=now)
+        if not lease:
+            continue
+        freshness = lease.get("freshness") or classify_lease_freshness(lease, now=now)
+        entry = {"pr_number": pr_number, "session_id": lease.get("session_id"), "freshness": freshness}
+        if freshness == "stale_warning":
+            stale.append(entry)
+        elif freshness == "reclaimable":
+            reclaimable.append(entry)
+        else:
+            active.append(entry)
+    return {
+        "active_review_leases": active,
+        "stale_review_leases": stale,
+        "reclaimable_review_leases": reclaimable,
+    }

scripts/worktree-start

@@ -38,13 +38,21 @@ fi
 branch="$1"
 start_ref="${2:-prgs/master}"
 
+script_dir="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+repo_root="$(cd "$script_dir/.." && pwd)"
+
 # Enforce issue-linked, traceable branch names (issue → branch → worktree → PR).
 if [[ "$allow_unlinked" -eq 0 ]]; then
-  if [[ ! -f "/tmp/gitea_issue_lock.json" ]]; then
-    echo "Error: Issue lock file '/tmp/gitea_issue_lock.json' is missing. You must lock exactly one issue before branch creation (fail closed)." >&2
+  locked_branch=$(python3 -c "
+import sys
+sys.path.insert(0, '$repo_root')
+import issue_lock_store
+print(issue_lock_store.resolve_locked_branch_for_session('$branch'))
+")
+  if [[ -z "$locked_branch" ]]; then
+    echo "Error: No session issue lock is bound. Call gitea_lock_issue before branch creation (fail closed)." >&2
     exit 2
   fi
-  locked_branch=$(python3 -c "import json; print(json.load(open('/tmp/gitea_issue_lock.json')).get('branch_name', ''))")
   if [[ "$branch" != "$locked_branch" ]]; then
     echo "Error: Requested branch '$branch' does not match locked branch '$locked_branch' (fail closed)." >&2
     exit 2
@@ -68,8 +76,6 @@ EOF
   fi
 fi
 
-script_dir="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
-repo_root="$(cd "$script_dir/.." && pwd)"
 worktree_name="${branch//\//-}"
 worktree_path="$repo_root/branches/$worktree_name"
 

skills/llm-project-workflow/workflows/review-merge-pr.md

@@ -732,6 +732,26 @@ The final report must identify:
 * whether same-PR merge continuation was allowed
 * whether the run stopped as required
 
+## 26B. Per-PR reviewer lease (#407)
+
+Parallel reviewer sessions are allowed only when each session holds a distinct,
+live PR lease.
+
+Before validation or review mutation on a selected PR:
+
+1. Call `gitea_acquire_reviewer_pr_lease` with worktree path, candidate head SHA,
+   and target branch SHA.
+2. Post heartbeats via `gitea_heartbeat_reviewer_pr_lease` before validation,
+   after validation, before review mutation, and before merge.
+3. Do not approve, request changes, or merge unless the in-session lease
+   matches the selected PR.
+
+If PR head or target branch advances during the lease, stop and refresh
+inventory before continuing.
+
+Final reports must include lease session id, acquisition proof, heartbeat
+status, and release/blocked status.
+
 ## 27. Merge rules
 
 Before merge, rerun fresh live checks:

tests/test_agent_temp_artifacts.py

@@ -74,21 +74,24 @@ ISSUE_WRITE_ENV = {
 
 class TestIssueLockArtifactWarning(unittest.TestCase):
     def setUp(self):
-        self._env_patcher = patch.dict(os.environ, ISSUE_WRITE_ENV, clear=True)
+        self._lock_dir = tempfile.TemporaryDirectory()
+        env = {**ISSUE_WRITE_ENV, "GITEA_ISSUE_LOCK_DIR": self._lock_dir.name}
+        self._env_patcher = patch.dict(os.environ, env, clear=True)
         self._env_patcher.start()
 
     def tearDown(self):
         self._env_patcher.stop()
+        self._lock_dir.cleanup()
 
     @patch(
         "mcp_server.issue_duplicate_context_fetcher",
         return_value=([], [], {"status": "not_claimed"}),
     )
+    @patch("mcp_server.api_get_all", return_value=[])
     @patch("mcp_server._auth", return_value="token x")
     @patch("mcp_server._resolve", return_value=("h", "o", "r"))
-    @patch("mcp_server.ISSUE_LOCK_FILE", new_callable=lambda: tempfile.mktemp())
     @patch("issue_lock_worktree.read_worktree_git_state")
-    def test_lock_success_includes_artifact_warning(self, mock_state, _lock_file, *_mocks):
+    def test_lock_success_includes_artifact_warning(self, mock_state, *_mocks):
         mock_state.return_value = {
             "current_branch": "master",
             "porcelain_status": "?? _emit_payload.py\n",

tests/test_audit.py

@@ -286,6 +286,21 @@ class TestSimpleToolAudit(_AuditWiringBase):
 
 class TestGatedToolAudit(_AuditWiringBase):
 
+    def setUp(self):
+        super().setUp()
+        from tests.test_mcp_server import _install_owned_reviewer_lease
+        import reviewer_pr_lease
+
+        self._lease_patch = _install_owned_reviewer_lease(8)
+        self._lease_patch.start()
+        self._auth_identity_patch = patch(
+            "mcp_server._authenticated_username", return_value="reviewer-bot"
+        )
+        self._auth_identity_patch.start()
+        self.addCleanup(self._auth_identity_patch.stop)
+        self.addCleanup(self._lease_patch.stop)
+        self.addCleanup(reviewer_pr_lease.clear_session_lease)
+
     def _pr(self, author, state="open", sha="abc123", mergeable=True):
         return {"user": {"login": author}, "state": state,
                 "head": {"sha": sha}, "mergeable": mergeable}
@@ -344,11 +359,22 @@ class TestGatedToolAudit(_AuditWiringBase):
                         GITEA_ALLOWED_OPERATIONS="read,review,approve")
         with patch.dict(os.environ, env, clear=True):
             from mcp_server import init_review_decision_lock, gitea_mark_final_review_decision
+            from tests.test_mcp_server import _install_owned_reviewer_lease
+            import reviewer_pr_lease
+
             init_review_decision_lock("prgs", "review_pr")
             gitea_mark_final_review_decision(8, "approve", remote="prgs")
-            r = gitea_submit_pr_review(pr_number=8, action="approve",
-                                       body="LGTM", remote="prgs",
-                                       final_review_decision_ready=True)
+            lease_patch = _install_owned_reviewer_lease(8)
+            lease_patch.start()
+            try:
+                r = gitea_submit_pr_review(
+                    pr_number=8, action="approve",
+                    body="LGTM", remote="prgs",
+                    final_review_decision_ready=True,
+                )
+            finally:
+                lease_patch.stop()
+                reviewer_pr_lease.clear_session_lease()
         self.assertTrue(r["performed"])
         recs = self._records()
         self.assertEqual(len(recs), 1)

tests/test_commit_payloads.py

@@ -66,9 +66,12 @@ class TestCommitPayloads(unittest.TestCase):
         )
         self.locked_worktree_path = os.path.realpath(self.locked_worktree_dir.name)
 
-        self.lock_file_path = "/tmp/gitea_issue_lock.json"
+        import issue_lock_store
         import issue_lock_provenance
 
+        self._lock_dir = tempfile.TemporaryDirectory()
+        os.environ["GITEA_ISSUE_LOCK_DIR"] = self._lock_dir.name
+
         work_lease = {
             "operation_type": "author_issue_work",
             "issue_number": 263,
@@ -89,8 +92,7 @@ class TestCommitPayloads(unittest.TestCase):
                 claimant=work_lease.get("claimant"),
             ),
         }
-        with open(self.lock_file_path, "w", encoding="utf-8") as fh:
-            fh.write(json.dumps(self.lock_data))
+        self.lock_file_path = issue_lock_store.bind_session_lock(self.lock_data)
 
         # Reset preflight status to bypass/pass verification in tests
         self.orig_whoami_called = mcp_server._preflight_whoami_called
@@ -114,8 +116,7 @@ class TestCommitPayloads(unittest.TestCase):
 
         self._dir.cleanup()
         self.locked_worktree_dir.cleanup()
-        if os.path.exists(self.lock_file_path):
-            os.remove(self.lock_file_path)
+        self._lock_dir.cleanup()
 
     def _env(self, profile: str) -> dict:
         return {
@@ -124,6 +125,7 @@ class TestCommitPayloads(unittest.TestCase):
             "GITEA_TOKEN_AUTHOR": "author-pass",
             "GITEA_TEST_PORCELAIN": "",
             "GITEA_AUTHOR_WORKTREE": self.locked_worktree_path,
+            "GITEA_ISSUE_LOCK_DIR": self._lock_dir.name,
         }
 
     @patch("mcp_server.api_request")

tests/test_issue_lock_adoption.py

@@ -0,0 +1,68 @@
+"""Unit tests for own-branch lock adoption decision (#442 / #443)."""
+import sys
+import unittest
+from pathlib import Path
+
+sys.path.insert(0, str(Path(__file__).resolve().parent.parent))
+
+from issue_lock_adoption import (  # noqa: E402
+    ADOPT,
+    BLOCK_COMPETING,
+    NO_MATCH,
+    assess_own_branch_adoption,
+    build_adoption_proof,
+)
+
+REQ = "feat/issue-420-server-code-parity"
+
+
+class TestAssessOwnBranchAdoption(unittest.TestCase):
+    def test_exact_own_branch_is_adopted(self):
+        result = assess_own_branch_adoption(
+            issue_number=420,
+            requested_branch=REQ,
+            existing_branches=[{"name": REQ, "commit_sha": "934688a"}],
+        )
+        self.assertEqual(result["outcome"], ADOPT)
+        self.assertTrue(result["adopt"])
+
+    def test_different_branch_same_issue_blocks(self):
+        result = assess_own_branch_adoption(
+            issue_number=420,
+            requested_branch=REQ,
+            existing_branches=[{"name": "feat/issue-420-other-work"}],
+        )
+        self.assertEqual(result["outcome"], BLOCK_COMPETING)
+        self.assertTrue(result["block"])
+
+    def test_no_matching_branch_is_normal_path(self):
+        result = assess_own_branch_adoption(
+            issue_number=420,
+            requested_branch=REQ,
+            existing_branches=[{"name": "feat/issue-999-unrelated"}],
+        )
+        self.assertEqual(result["outcome"], NO_MATCH)
+
+
+class TestBuildAdoptionProof(unittest.TestCase):
+    def test_proof_has_required_fields(self):
+        assessment = assess_own_branch_adoption(
+            issue_number=420,
+            requested_branch=REQ,
+            existing_branches=[{"name": REQ, "commit_sha": "934688a"}],
+        )
+        proof = build_adoption_proof(
+            issue_number=420,
+            branch_name=REQ,
+            assessment=assessment,
+            open_pr_checked=True,
+            competing_lock_checked=True,
+            lock_file_path="/tmp/example-lock.json",
+            lock_file_status="written",
+        )
+        self.assertEqual(proof["branch_head_commit"], "934688a")
+        self.assertTrue(proof["no_existing_pr_proof"])
+
+
+if __name__ == "__main__":
+    unittest.main()

tests/test_issue_lock_store.py

@@ -0,0 +1,181 @@
+"""Unit tests for keyed issue-lock storage (#443)."""
+import json
+import os
+import sys
+import tempfile
+import unittest
+from datetime import datetime, timedelta, timezone
+from pathlib import Path
+from unittest import mock
+
+sys.path.insert(0, str(Path(__file__).resolve().parent.parent))
+
+import issue_lock_store as ils  # noqa: E402
+
+
+def _lease(expires_at: str) -> dict:
+    return {
+        "operation_type": ils.AUTHOR_ISSUE_WORK_LEASE,
+        "expires_at": expires_at,
+        "created_at": "2026-01-01T00:00:00Z",
+        "last_heartbeat_at": "2026-01-01T00:00:00Z",
+    }
+
+
+def _lock_record(**overrides) -> dict:
+    record = {
+        "issue_number": 420,
+        "branch_name": "feat/issue-420-server-code-parity",
+        "remote": "prgs",
+        "org": "Scaled-Tech-Consulting",
+        "repo": "Gitea-Tools",
+        "worktree_path": "/tmp/wt-420",
+        "work_lease": _lease("2999-01-01T00:00:00Z"),
+    }
+    record.update(overrides)
+    return record
+
+
+class TestIssueLockStore(unittest.TestCase):
+    def setUp(self):
+        self._dir = tempfile.TemporaryDirectory()
+        self.lock_dir = self._dir.name
+        self._env = mock.patch.dict(os.environ, {"GITEA_ISSUE_LOCK_DIR": self.lock_dir})
+        self._env.start()
+
+    def tearDown(self):
+        self._env.stop()
+        self._dir.cleanup()
+
+    def test_concurrent_repo_locks_do_not_overwrite(self):
+        lock_a = _lock_record(
+            issue_number=108,
+            branch_name="feat/issue-108-root-menu",
+            repo="mcp-control-plane",
+            worktree_path="/tmp/wt-108",
+        )
+        lock_b = _lock_record(
+            issue_number=420,
+            branch_name="feat/issue-420-server-code-parity",
+            repo="Gitea-Tools",
+            worktree_path="/tmp/wt-420",
+        )
+        path_a = ils.bind_session_lock(lock_a)
+        with mock.patch("os.getpid", return_value=9999):
+            path_b = ils.bind_session_lock(lock_b)
+
+        self.assertNotEqual(path_a, path_b)
+        self.assertTrue(os.path.exists(path_a))
+        self.assertTrue(os.path.exists(path_b))
+        stored_a = ils.read_lock_file(path_a)
+        stored_b = ils.read_lock_file(path_b)
+        self.assertEqual(stored_a["issue_number"], 108)
+        self.assertEqual(stored_b["issue_number"], 420)
+
+    def test_concurrent_issue_locks_same_repo_do_not_overwrite(self):
+        lock_a = _lock_record(issue_number=427, branch_name="feat/issue-427-a")
+        lock_b = _lock_record(issue_number=428, branch_name="feat/issue-428-b")
+        path_a = ils.bind_session_lock(lock_a)
+        with mock.patch("os.getpid", return_value=4242):
+            path_b = ils.bind_session_lock(lock_b)
+
+        self.assertNotEqual(path_a, path_b)
+        self.assertEqual(ils.read_lock_file(path_a)["issue_number"], 427)
+        self.assertEqual(ils.read_lock_file(path_b)["issue_number"], 428)
+
+    def test_foreign_live_lease_blocks_overwrite(self):
+        existing = _lock_record(
+            branch_name="feat/issue-420-other",
+            worktree_path="/tmp/other",
+            work_lease=_lease("2999-01-01T00:00:00Z"),
+        )
+        path = ils.lock_file_path(
+            remote="prgs",
+            org="Scaled-Tech-Consulting",
+            repo="Gitea-Tools",
+            issue_number=420,
+        )
+        ils.save_lock_file(path, existing)
+
+        incoming = _lock_record(worktree_path="/tmp/mine")
+        block = ils.assess_foreign_lock_overwrite(existing, incoming)
+        self.assertIn("live foreign issue lock", block or "")
+
+    def test_expired_lease_allows_takeover_with_conflict_check(self):
+        existing = _lock_record(
+            branch_name="feat/issue-420-other",
+            worktree_path="/tmp/other",
+            work_lease=_lease("2000-01-01T00:00:00Z"),
+        )
+        incoming = _lock_record(worktree_path="/tmp/mine")
+        self.assertIsNone(ils.assess_foreign_lock_overwrite(existing, incoming))
+        block = ils.assess_same_issue_lease_conflict(
+            existing,
+            issue_number=420,
+            branch_name="feat/issue-420-server-code-parity",
+            worktree_path="/tmp/mine",
+        )
+        self.assertIn("Recovery review is required", block or "")
+
+    def test_same_owner_lease_conflict_allows_refresh(self):
+        worktree = "/tmp/wt-420"
+        existing = _lock_record(worktree_path=worktree)
+        block = ils.assess_same_issue_lease_conflict(
+            existing,
+            issue_number=420,
+            branch_name="feat/issue-420-server-code-parity",
+            worktree_path=worktree,
+        )
+        self.assertIsNone(block)
+
+    def test_find_lock_for_branch_after_restart(self):
+        record = _lock_record()
+        path = ils.lock_file_path(
+            remote="prgs",
+            org="Scaled-Tech-Consulting",
+            repo="Gitea-Tools",
+            issue_number=420,
+        )
+        ils.save_lock_file(path, record)
+
+        with mock.patch("os.getpid", return_value=5555):
+            self.assertIsNone(ils.read_session_issue_lock())
+
+        found = ils.find_lock_for_branch(
+            remote="prgs",
+            org="Scaled-Tech-Consulting",
+            repo="Gitea-Tools",
+            branch_name="feat/issue-420-server-code-parity",
+        )
+        self.assertEqual(found["issue_number"], 420)
+
+    def test_has_active_issue_lock_scans_keyed_store(self):
+        ils.bind_session_lock(_lock_record())
+        self.assertTrue(
+            ils.has_active_issue_lock("feat/issue-420-server-code-parity")
+        )
+        self.assertFalse(ils.has_active_issue_lock("feat/issue-999-other"))
+
+    def test_atomic_write_preserves_unrelated_lock(self):
+        path_a = ils.lock_file_path(
+            remote="prgs",
+            org="Scaled-Tech-Consulting",
+            repo="Gitea-Tools",
+            issue_number=108,
+        )
+        ils.save_lock_file(path_a, _lock_record(issue_number=108, repo="mcp-control-plane"))
+        path_b = ils.lock_file_path(
+            remote="prgs",
+            org="Scaled-Tech-Consulting",
+            repo="Gitea-Tools",
+            issue_number=420,
+        )
+        ils.save_lock_file(path_b, _lock_record())
+
+        self.assertTrue(os.path.exists(path_a))
+        self.assertTrue(os.path.exists(path_b))
+        self.assertEqual(ils.read_lock_file(path_a)["issue_number"], 108)
+
+
+if __name__ == "__main__":
+    unittest.main()

tests/test_issue_work_duplicate_gate.py

@@ -1,5 +1,4 @@
 """Tests for early duplicate-work detection (#400)."""
-import json
 import os
 import sys
 import tempfile
@@ -9,6 +8,8 @@ from unittest.mock import patch
 
 sys.path.insert(0, str(Path(__file__).resolve().parent.parent))
 
+import issue_lock_provenance
+import issue_lock_store
 import issue_work_duplicate_gate as dup_gate
 import mcp_server
 from issue_work_duplicate_gate import (
@@ -122,8 +123,9 @@ class TestDuplicateReportOutcome(unittest.TestCase):
 
 
 class TestInjectableDuplicateFetcher(unittest.TestCase):
+    @patch("mcp_server.api_get_all", return_value=[])
     @patch("mcp_server.get_auth_header", return_value="token x")
-    def test_lock_issue_uses_injected_fetcher(self, _auth):
+    def test_lock_issue_uses_injected_fetcher(self, _auth, _api):
         seen = {}
 
         def fetcher(h, o, r, auth, issue_number):
@@ -140,26 +142,29 @@ class TestInjectableDuplicateFetcher(unittest.TestCase):
                 "porcelain_status": "",
                 "base_equivalent": True,
             },
-        ), patch.dict(os.environ, {
-            "GITEA_ALLOWED_OPERATIONS": "gitea.issue.comment",
-        }, clear=True):
-            with patch.object(mcp_server, "ISSUE_LOCK_FILE", tempfile.mktemp()):
-                mcp_server.gitea_lock_issue(
-                    issue_number=400,
-                    branch_name="feat/issue-400-duplicate-work-preflight",
-                    remote="prgs",
-                )
+        ):
+            with tempfile.TemporaryDirectory() as lock_dir:
+                with patch.dict(os.environ, {
+                    "GITEA_ALLOWED_OPERATIONS": "gitea.issue.comment",
+                    "GITEA_ISSUE_LOCK_DIR": lock_dir,
+                }, clear=True):
+                    mcp_server.gitea_lock_issue(
+                        issue_number=400,
+                        branch_name="feat/issue-400-duplicate-work-preflight",
+                        remote="prgs",
+                    )
         self.assertEqual(seen["issue_number"], 400)
 
 
 class TestMcpDuplicateRecheck(unittest.TestCase):
     def setUp(self):
         self._dir = tempfile.TemporaryDirectory()
-        self.lock_path = os.path.join(self._dir.name, "gitea_issue_lock.json")
-        self._lock_patch = patch.object(
-            mcp_server, "ISSUE_LOCK_FILE", self.lock_path
+        self._env_patch = patch.dict(
+            os.environ,
+            {"GITEA_ISSUE_LOCK_DIR": self._dir.name},
+            clear=False,
         )
-        self._lock_patch.start()
+        self._env_patch.start()
         self._remotes = patch.dict(mcp_server.REMOTES, {
             "prgs": {"host": "gitea.example.com", "org": "Example-Org",
                      "repo": "Example-Repo"},
@@ -172,12 +177,27 @@ class TestMcpDuplicateRecheck(unittest.TestCase):
         self._dir.cleanup()
 
     def _write_lock(self, issue_number=400, branch="feat/issue-400-x"):
-        with open(self.lock_path, "w", encoding="utf-8") as fh:
-            json.dump({
-                "issue_number": issue_number,
-                "branch_name": branch,
-                "remote": "prgs",
-            }, fh)
+        worktree_path = os.path.realpath(os.getcwd())
+        work_lease = {
+            "operation_type": "author_issue_work",
+            "issue_number": issue_number,
+            "branch": branch,
+            "claimant": {"username": "test-user", "profile": "test-author"},
+            "expires_at": "2999-01-01T00:00:00Z",
+        }
+        issue_lock_store.bind_session_lock({
+            "issue_number": issue_number,
+            "branch_name": branch,
+            "remote": "prgs",
+            "org": "Example-Org",
+            "repo": "Example-Repo",
+            "worktree_path": worktree_path,
+            "work_lease": work_lease,
+            "lock_provenance": issue_lock_provenance.build_sanctioned_lock_provenance(
+                tool="gitea_lock_issue",
+                claimant=work_lease.get("claimant"),
+            ),
+        })
 
     @patch("mcp_server._assess_issue_duplicate_gate")
     @patch("mcp_server.get_profile", return_value={
@@ -241,6 +261,7 @@ class TestMcpDuplicateRecheck(unittest.TestCase):
                 base="master",
                 body="Closes #400",
                 remote="prgs",
+                worktree_path=os.path.realpath(os.getcwd()),
             )
         self.assertFalse(result["success"])
         self.assertIsNone(result.get("number"))

tests/test_mcp_server.py

@@ -6,6 +6,7 @@ the MCP protocol) with mocked API responses.
 import json
 import os
 import sys
+import tempfile
 import unittest
 from unittest.mock import patch, MagicMock
 
@@ -45,6 +46,7 @@ from gitea_auth import get_profile  # noqa: E402
 import gitea_config  # noqa: E402
 
 import mcp_server
+import issue_lock_store
 
 FAKE_AUTH = "Basic dGVzdDp0ZXN0"
 
@@ -79,6 +81,64 @@ def _visible_approval_reviews(reviewer="reviewer-bot", sha="abc123"):
     return [_formal_review(reviewer, "APPROVED", sha=sha)]
 
 
+_DEFAULT_LEASE_SESSION = "mcp-test-reviewer-lease"
+
+
+def _reviewer_lease_comment(
+    pr_number,
+    *,
+    session_id=_DEFAULT_LEASE_SESSION,
+    head_sha="abc123",
+    reviewer="reviewer-bot",
+):
+    from datetime import datetime, timezone
+
+    import reviewer_pr_lease
+
+    body = reviewer_pr_lease.format_lease_body(
+        repo="Scaled-Tech-Consulting/Gitea-Tools",
+        pr_number=pr_number,
+        issue_number=407,
+        reviewer_identity=reviewer,
+        profile="gitea-reviewer",
+        session_id=session_id,
+        worktree="branches/review-test",
+        phase="claimed",
+        candidate_head=head_sha,
+        target_branch="master",
+        target_branch_sha="b" * 40,
+        last_activity=datetime.now(timezone.utc),
+    )
+    return {"id": 9001, "body": body, "user": {"login": reviewer}}
+
+
+def _install_owned_reviewer_lease(
+    pr_number,
+    *,
+    session_id=_DEFAULT_LEASE_SESSION,
+    head_sha="abc123",
+):
+    import reviewer_pr_lease
+
+    reviewer_pr_lease.clear_session_lease()
+    reviewer_pr_lease.record_session_lease({
+        "pr_number": pr_number,
+        "session_id": session_id,
+        "candidate_head": head_sha,
+        "target_branch": "master",
+    })
+    return patch(
+        "mcp_server._fetch_pr_comments",
+        return_value=[
+            _reviewer_lease_comment(
+                pr_number,
+                session_id=session_id,
+                head_sha=head_sha,
+            )
+        ],
+    )
+
+
 # Issue-write tools are profile-gated (#69).
 ISSUE_WRITE_ENV = {
     "GITEA_ALLOWED_OPERATIONS": (
@@ -116,6 +176,7 @@ def _sample_issue_lock(issue_number=123, branch_name="feat/x", **overrides):
         "remote": "dadeschools",
         "org": "Scaled-Tech-Consulting",
         "repo": "Gitea-Tools",
+        "worktree_path": "/tmp/test-worktree",
         "work_lease": work_lease,
         "lock_provenance": issue_lock_provenance.build_sanctioned_lock_provenance(
             tool="gitea_lock_issue",
@@ -131,6 +192,17 @@ def _clear_duplicate_context_fetcher(*_args, **_kwargs):
     return [], [], {"status": "not_claimed"}
 
 
+def _bind_test_lock(**overrides) -> str:
+    remote = overrides.get("remote", "dadeschools")
+    record = _sample_issue_lock(**overrides)
+    if remote in mcp_server.REMOTES:
+        profile = mcp_server.REMOTES[remote]
+        record.setdefault("org", profile["org"])
+        record.setdefault("repo", profile["repo"])
+    record["remote"] = remote
+    return issue_lock_store.bind_session_lock(record)
+
+
 # ---------------------------------------------------------------------------
 # Create Issue
 # ---------------------------------------------------------------------------
@@ -193,18 +265,21 @@ class TestCreatePR(unittest.TestCase):
            return_value=(True, []))
     @patch("mcp_server.api_request")
     @patch("mcp_server.get_auth_header", return_value=FAKE_AUTH)
-    @patch("os.path.exists", return_value=True)
-    @patch("builtins.open")
-    def test_creates_pr(self, mock_open, mock_exists, _auth, mock_api, _role, _dup_fetcher):
-        lock_json = json.dumps(_sample_issue_lock(issue_number=123, branch_name="feat/x"))
-        mock_open.return_value.__enter__.return_value.read.return_value = lock_json
+    def test_creates_pr(self, _auth, mock_api, _role, _dup_fetcher):
+        worktree = os.path.realpath(os.getcwd())
         mock_api.return_value = {"number": 3, "html_url": "https://example.com/pulls/3"}
-        with patch.dict(os.environ, CREATE_PR_ENV, clear=True):
-            result = gitea_create_pr(title="feat: X Closes #123", head="feat/x", base="main")
+        with tempfile.TemporaryDirectory() as lock_dir:
+            env = {**CREATE_PR_ENV, "GITEA_ISSUE_LOCK_DIR": lock_dir}
+            with patch.dict(os.environ, env, clear=True):
+                _bind_test_lock(issue_number=123, branch_name="feat/x", worktree_path=worktree)
+                result = gitea_create_pr(
+                    title="feat: X Closes #123",
+                    head="feat/x",
+                    base="main",
+                    worktree_path=worktree,
+                )
         self.assertEqual(result["number"], 3)
         self.assertNotIn("url", result)
-        mock_exists.assert_called_with(ISSUE_LOCK_FILE)
-        mock_open.assert_called_with(ISSUE_LOCK_FILE, "r", encoding="utf-8")
         payload = mock_api.call_args[0][3]
         self.assertEqual(payload["head"], "feat/x")
         self.assertEqual(payload["base"], "main")
@@ -218,30 +293,42 @@ class TestCreatePR(unittest.TestCase):
            return_value=(True, []))
     @patch("mcp_server.api_request")
     @patch("mcp_server.get_auth_header", return_value=FAKE_AUTH)
-    @patch("os.path.exists", return_value=True)
-    @patch("builtins.open")
-    def test_create_pr_reveal_opt_in_includes_url(self, mock_open, mock_exists, _auth, mock_api, _role, _dup_fetcher):
-        lock_json = json.dumps(_sample_issue_lock(issue_number=123, branch_name="feat/x"))
-        mock_open.return_value.__enter__.return_value.read.return_value = lock_json
+    def test_create_pr_reveal_opt_in_includes_url(self, _auth, mock_api, _role, _dup_fetcher):
+        worktree = os.path.realpath(os.getcwd())
         mock_api.return_value = {"number": 3, "html_url": "https://example.com/pulls/3"}
-        env = {**CREATE_PR_ENV, "GITEA_MCP_REVEAL_ENDPOINTS": "1"}
-        with patch.dict(os.environ, env, clear=True):
-            result = gitea_create_pr(title="feat: X Closes #123", head="feat/x", base="main")
+        with tempfile.TemporaryDirectory() as lock_dir:
+            env = {**CREATE_PR_ENV, "GITEA_ISSUE_LOCK_DIR": lock_dir, "GITEA_MCP_REVEAL_ENDPOINTS": "1"}
+            with patch.dict(os.environ, env, clear=True):
+                _bind_test_lock(issue_number=123, branch_name="feat/x", worktree_path=worktree)
+                result = gitea_create_pr(
+                    title="feat: X Closes #123",
+                    head="feat/x",
+                    base="main",
+                    worktree_path=worktree,
+                )
         self.assertIn("pulls/3", result["url"])
 
     @patch("mcp_server.role_session_router.check_author_mutation_after_reviewer_stop",
            return_value=(True, []))
     @patch("mcp_server.get_auth_header", return_value=FAKE_AUTH)
-    @patch("os.path.exists", return_value=True)
-    @patch("builtins.open")
-    def test_create_pr_locked_issue_mismatch_fails(self, mock_open, mock_exists, _auth, _role):
-        lock_json = json.dumps(_sample_issue_lock(issue_number=123, branch_name="feat/x"))
-        mock_open.return_value.__enter__.return_value.read.return_value = lock_json
-        with patch.dict(os.environ, CREATE_PR_ENV, clear=True):
-            with self.assertRaises(ValueError) as ctx:
-                gitea_create_pr(title="feat: X Closes #999", head="feat/x", base="main")
+    def test_create_pr_locked_issue_mismatch_fails(self, _auth, _role):
+        worktree = os.path.realpath(os.getcwd())
+        with tempfile.TemporaryDirectory() as lock_dir:
+            env = {**CREATE_PR_ENV, "GITEA_ISSUE_LOCK_DIR": lock_dir}
+            with patch.dict(os.environ, env, clear=True):
+                _bind_test_lock(
+                    issue_number=123,
+                    branch_name="feat/x",
+                    worktree_path=worktree,
+                )
+                with self.assertRaises(ValueError) as ctx:
+                    gitea_create_pr(
+                        title="feat: X Closes #999",
+                        head="feat/x",
+                        base="main",
+                        worktree_path=worktree,
+                    )
         self.assertIn("Closes #123", str(ctx.exception))
-        mock_open.assert_called_with(ISSUE_LOCK_FILE, "r", encoding="utf-8")
 
 
 # ---------------------------------------------------------------------------
@@ -539,6 +626,19 @@ class TestViewPR(unittest.TestCase):
 class TestMergePR(unittest.TestCase):
     """Gated merge workflow (#16). gitea_merge_pr is the only merge path."""
 
+    def setUp(self):
+        import reviewer_pr_lease
+
+        self._lease_patch = _install_owned_reviewer_lease(8)
+        self._lease_patch.start()
+        self._auth_identity_patch = patch(
+            "mcp_server._authenticated_username", return_value="reviewer-bot"
+        )
+        self._auth_identity_patch.start()
+        self.addCleanup(self._auth_identity_patch.stop)
+        self.addCleanup(self._lease_patch.stop)
+        self.addCleanup(reviewer_pr_lease.clear_session_lease)
+
     def _pr(self, author, state="open", sha="abc123", mergeable=True):
         return {
             "user": {"login": author},
@@ -799,9 +899,11 @@ class TestMergePR(unittest.TestCase):
                 pr_number=8, confirmation=self._confirm(8),
                 expected_head_sha="deadbeef", remote="prgs")
         self.assertFalse(r["performed"])
-        self.assertIn(
-            "expected head SHA does not match current PR head (fail closed)",
-            r["reasons"])
+        self.assertTrue(any(
+            "expected head SHA does not match current PR head (fail closed)" in reason
+            or "PR head changed during lease" in reason
+            for reason in r["reasons"]
+        ))
         self._assert_no_merge_call(mock_api)
 
     @patch("mcp_server.api_request")
@@ -1680,7 +1782,20 @@ class TestReviewDecisionValidationGate(unittest.TestCase):
         }
 
     def setUp(self):
+        import reviewer_pr_lease
+
         init_review_decision_lock("prgs", "review_pr")
+        self._lease_patch = _install_owned_reviewer_lease(
+            self.PR, head_sha=self.SHA,
+        )
+        self._lease_patch.start()
+        self._auth_identity_patch = patch(
+            "mcp_server._authenticated_username", return_value="reviewer-bot"
+        )
+        self._auth_identity_patch.start()
+        self.addCleanup(self._auth_identity_patch.stop)
+        self.addCleanup(self._lease_patch.stop)
+        self.addCleanup(reviewer_pr_lease.clear_session_lease)
 
     def _env(self):
         return patch.dict(os.environ, {
@@ -1775,8 +1890,19 @@ class TestSubmitPrReview(unittest.TestCase):
     """Gated review-mutation tool (#15)."""
 
     def setUp(self):
+        import reviewer_pr_lease
+
         init_review_decision_lock("prgs", "review_pr")
         gitea_mark_final_review_decision(8, "approve", remote="prgs")
+        self._lease_patch = _install_owned_reviewer_lease(8)
+        self._lease_patch.start()
+        self._auth_identity_patch = patch(
+            "mcp_server._authenticated_username", return_value="reviewer-bot"
+        )
+        self._auth_identity_patch.start()
+        self.addCleanup(self._auth_identity_patch.stop)
+        self.addCleanup(self._lease_patch.stop)
+        self.addCleanup(reviewer_pr_lease.clear_session_lease)
 
     def _pr(self, author, state="open", sha="abc123", mergeable=True):
         return {
@@ -2014,9 +2140,11 @@ class TestSubmitPrReview(unittest.TestCase):
                     final_review_decision_ready=True,
                 )
             self.assertFalse(r["performed"])
-            self.assertIn(
-                "expected head SHA does not match current PR head (fail closed)",
-                r["reasons"])
+            self.assertTrue(any(
+                "expected head SHA does not match current PR head (fail closed)" in reason
+                or "PR head changed during lease" in reason
+                for reason in r["reasons"]
+            ))
             self._assert_no_mutation(mock_api)
 
     def test_head_sha_match_allows(self):
@@ -2079,9 +2207,9 @@ class TestSubmitPrReview(unittest.TestCase):
         env = {"GITEA_PROFILE_NAME": "gitea-reviewer",
                "GITEA_ALLOWED_OPERATIONS": "read,review,approve"}
         with patch.dict(os.environ, env, clear=True):
-            gitea_mark_final_review_decision(5, "approve", remote="prgs")
+            gitea_mark_final_review_decision(8, "approve", remote="prgs")
             r = gitea_submit_pr_review(
-                pr_number=5, action="approve", remote="prgs",
+                pr_number=8, action="approve", remote="prgs",
                 final_review_decision_ready=True,
             )
         self.assertFalse(r["performed"])
@@ -2300,6 +2428,13 @@ class TestTrackerHygieneCleanup(unittest.TestCase):
         self.assertEqual(res["cleanup_status"].get(1), "not present")
 
     def test_merge_pr_with_closes_removes_label(self):
+        import reviewer_pr_lease
+
+        lease_patch = _install_owned_reviewer_lease(1, head_sha="sha123")
+        lease_patch.start()
+        self.addCleanup(lease_patch.stop)
+        self.addCleanup(reviewer_pr_lease.clear_session_lease)
+
         def api_side_effect(method, url, auth, payload=None):
             if method == "GET" and "/user" in url:
                 return {"login": "merger"}
@@ -2334,6 +2469,13 @@ class TestTrackerHygieneCleanup(unittest.TestCase):
         self.assertEqual(res["cleanup_status"].get(123), "released")
 
     def test_merge_pr_with_branch_name_removes_label(self):
+        import reviewer_pr_lease
+
+        lease_patch = _install_owned_reviewer_lease(1, head_sha="sha123")
+        lease_patch.start()
+        self.addCleanup(lease_patch.stop)
+        self.addCleanup(reviewer_pr_lease.clear_session_lease)
+
         def api_side_effect(method, url, auth, payload=None):
             if method == "GET" and "/user" in url:
                 return {"login": "merger"}
@@ -3015,10 +3157,12 @@ class TestVerifyMutationAuthority(unittest.TestCase):
         # profile; the active profile resolves as reviewer — side-channel
         # override rejected even with a matching in-process authority.
         self._authority()
-        with patch.dict(os.environ,
-                        {"GITEA_SESSION_PROFILE_LOCK": "prgs-author"}):
-            with self.assertRaises(RuntimeError) as ctx:
-                mcp_server.verify_mutation_authority("prgs")
+        with patch("mcp_server.gitea_config.is_runtime_switching_enabled",
+                   return_value=False):
+            with patch.dict(os.environ,
+                            {"GITEA_SESSION_PROFILE_LOCK": "prgs-author"}):
+                with self.assertRaises(RuntimeError) as ctx:
+                    mcp_server.verify_mutation_authority("prgs")
         self.assertIn("side-channel override rejected", str(ctx.exception))
 
     def test_foreign_pid_authority_is_not_trusted(self):
@@ -3069,7 +3213,12 @@ class TestIssueLocking(unittest.TestCase):
     """Test issue locking and PR gating constraints."""
 
     def setUp(self):
-        self._env_patcher = patch.dict(os.environ, ISSUE_WRITE_ENV, clear=True)
+        self._lock_dir = tempfile.TemporaryDirectory()
+        env = {
+            **ISSUE_WRITE_ENV,
+            "GITEA_ISSUE_LOCK_DIR": self._lock_dir.name,
+        }
+        self._env_patcher = patch.dict(os.environ, env, clear=True)
         self._env_patcher.start()
         self._dup_fetcher_patcher = patch(
             "mcp_server.issue_duplicate_context_fetcher",
@@ -3080,15 +3229,21 @@ class TestIssueLocking(unittest.TestCase):
     def tearDown(self):
         self._dup_fetcher_patcher.stop()
         self._env_patcher.stop()
-        if os.path.exists(ISSUE_LOCK_FILE):
-            os.remove(ISSUE_LOCK_FILE)
+        self._lock_dir.cleanup()
+
+    def _create_pr_env(self) -> dict:
+        return {
+            **CREATE_PR_ENV,
+            "GITEA_ISSUE_LOCK_DIR": self._lock_dir.name,
+        }
 
     @patch(
         "mcp_server.issue_lock_worktree.read_worktree_git_state",
         return_value=_clean_master_git_state_for_lock(),
     )
+    @patch("mcp_server.api_get_all", return_value=[])
     @patch("mcp_server.get_auth_header", return_value=FAKE_AUTH)
-    def test_lock_issue_success(self, _auth, _git_state):
+    def test_lock_issue_success(self, _auth, _api, _git_state):
         res = gitea_lock_issue(issue_number=196, branch_name="feat/issue-196-mutations", remote="prgs")
         self.assertTrue(res["success"])
         self.assertEqual(res["work_lease"]["operation_type"], "author_issue_work")
@@ -3098,9 +3253,8 @@ class TestIssueLocking(unittest.TestCase):
         self.assertIn("expires_at", res["work_lease"])
         self.assertIn("last_heartbeat_at", res["work_lease"])
         self.assertEqual(res["work_lease"]["claimant"]["profile"], "gitea-default")
-        self.assertTrue(os.path.exists(ISSUE_LOCK_FILE))
-        with open(ISSUE_LOCK_FILE, encoding="utf-8") as f:
-            lock = json.load(f)
+        self.assertIn("lock_file_path", res)
+        lock = issue_lock_store.read_lock_file(res["lock_file_path"])
         self.assertIn("worktree_path", lock)
         self.assertIn("work_lease", lock)
 
@@ -3156,32 +3310,81 @@ class TestIssueLocking(unittest.TestCase):
             gitea_lock_issue(issue_number=196, branch_name="feat/issue-196-mutations", remote="prgs")
         self.assertIn("remote branch(es) already match issue pattern", str(ctx.exception))
 
-    def test_lock_issue_blocks_active_same_operation_lease(self):
-        with open(ISSUE_LOCK_FILE, "w", encoding="utf-8") as f:
-            json.dump({
+    @patch(
+        "mcp_server.issue_lock_worktree.read_worktree_git_state",
+        return_value=_clean_master_git_state_for_lock(),
+    )
+    @patch("mcp_server.api_get_all")
+    @patch("mcp_server.get_auth_header", return_value=FAKE_AUTH)
+    def test_lock_issue_adopts_exact_own_branch(self, _auth, mock_api, _git_state):
+        branch = "feat/issue-196-mutations"
+        self.mock_dup_fetcher.return_value = ([], [branch], {"status": "not_claimed"})
+        mock_api.return_value = [{"name": branch, "commit": {"id": "abc123"}}]
+        res = gitea_lock_issue(issue_number=196, branch_name=branch, remote="prgs")
+        self.assertTrue(res["success"])
+        self.assertIn("adoption", res)
+        self.assertEqual(res["adoption"]["branch_head_commit"], "abc123")
+
+    @patch(
+        "mcp_server.issue_lock_worktree.read_worktree_git_state",
+        return_value=_clean_master_git_state_for_lock(),
+    )
+    @patch("mcp_server.api_get_all", return_value=[])
+    @patch("mcp_server.get_auth_header", return_value=FAKE_AUTH)
+    def test_lock_issue_blocks_active_same_operation_lease(self, _auth, _api, _git_state):
+        prgs_repo = mcp_server.REMOTES["prgs"]["repo"]
+        issue_lock_store.save_lock_file(
+            issue_lock_store.lock_file_path(
+                remote="prgs",
+                org="Scaled-Tech-Consulting",
+                repo=prgs_repo,
+                issue_number=196,
+            ),
+            {
                 "issue_number": 196,
                 "branch_name": "feat/issue-196-other-work",
+                "remote": "prgs",
+                "org": "Scaled-Tech-Consulting",
+                "repo": prgs_repo,
                 "worktree_path": "/tmp/other-worktree",
                 "work_lease": {
                     "operation_type": "author_issue_work",
                     "expires_at": "2999-01-01T00:00:00Z",
                 },
-            }, f)
+            },
+        )
         with self.assertRaises(RuntimeError) as ctx:
             gitea_lock_issue(issue_number=196, branch_name="feat/issue-196-mutations", remote="prgs")
         self.assertIn("already has an active author_issue_work lease", str(ctx.exception))
 
-    def test_lock_issue_blocks_expired_same_operation_lease_for_recovery(self):
-        with open(ISSUE_LOCK_FILE, "w", encoding="utf-8") as f:
-            json.dump({
+    @patch(
+        "mcp_server.issue_lock_worktree.read_worktree_git_state",
+        return_value=_clean_master_git_state_for_lock(),
+    )
+    @patch("mcp_server.api_get_all", return_value=[])
+    @patch("mcp_server.get_auth_header", return_value=FAKE_AUTH)
+    def test_lock_issue_blocks_expired_same_operation_lease_for_recovery(self, _auth, _api, _git_state):
+        prgs_repo = mcp_server.REMOTES["prgs"]["repo"]
+        issue_lock_store.save_lock_file(
+            issue_lock_store.lock_file_path(
+                remote="prgs",
+                org="Scaled-Tech-Consulting",
+                repo=prgs_repo,
+                issue_number=196,
+            ),
+            {
                 "issue_number": 196,
                 "branch_name": "feat/issue-196-other-work",
+                "remote": "prgs",
+                "org": "Scaled-Tech-Consulting",
+                "repo": prgs_repo,
                 "worktree_path": "/tmp/other-worktree",
                 "work_lease": {
                     "operation_type": "author_issue_work",
                     "expires_at": "2000-01-01T00:00:00Z",
                 },
-            }, f)
+            },
+        )
         with self.assertRaises(RuntimeError) as ctx:
             gitea_lock_issue(issue_number=196, branch_name="feat/issue-196-mutations", remote="prgs")
         self.assertIn("Recovery review is required before takeover", str(ctx.exception))
@@ -3248,9 +3451,7 @@ class TestIssueLocking(unittest.TestCase):
            return_value=(True, []))
     @patch("mcp_server.get_auth_header", return_value=FAKE_AUTH)
     def test_create_pr_missing_lock_fails(self, _auth, _role):
-        if os.path.exists(ISSUE_LOCK_FILE):
-            os.remove(ISSUE_LOCK_FILE)
-        with patch.dict(os.environ, CREATE_PR_ENV, clear=True):
+        with patch.dict(os.environ, self._create_pr_env(), clear=True):
             with self.assertRaises(RuntimeError) as ctx:
                 gitea_create_pr(title="feat: X Closes #196", head="feat/issue-196-mutations", remote="prgs")
         self.assertIn("Issue lock is missing", str(ctx.exception))
@@ -3259,37 +3460,64 @@ class TestIssueLocking(unittest.TestCase):
            return_value=(True, []))
     @patch("mcp_server.get_auth_header", return_value=FAKE_AUTH)
     def test_create_pr_branch_mismatch_fails(self, _auth, _role):
-        with open(ISSUE_LOCK_FILE, "w", encoding="utf-8") as f:
-            json.dump(_sample_issue_lock(
-                issue_number=196, branch_name="feat/issue-196-mutations"), f)
-        with patch.dict(os.environ, CREATE_PR_ENV, clear=True):
+        worktree = os.path.realpath(os.getcwd())
+        _bind_test_lock(
+            issue_number=196,
+            branch_name="feat/issue-196-mutations",
+            remote="prgs",
+            worktree_path=worktree,
+        )
+        with patch.dict(os.environ, self._create_pr_env(), clear=True):
             with self.assertRaises(ValueError) as ctx:
-                gitea_create_pr(title="feat: X Closes #196", head="feat/issue-196-different", remote="prgs")
+                gitea_create_pr(
+                    title="feat: X Closes #196",
+                    head="feat/issue-196-different",
+                    remote="prgs",
+                    worktree_path=worktree,
+                )
         self.assertIn("does not match locked branch", str(ctx.exception))
 
     @patch("mcp_server.role_session_router.check_author_mutation_after_reviewer_stop",
            return_value=(True, []))
     @patch("mcp_server.get_auth_header", return_value=FAKE_AUTH)
     def test_create_pr_forbidden_terms_fails(self, _auth, _role):
-        with open(ISSUE_LOCK_FILE, "w", encoding="utf-8") as f:
-            json.dump(_sample_issue_lock(
-                issue_number=196, branch_name="feat/issue-196-mutations"), f)
-        with patch.dict(os.environ, CREATE_PR_ENV, clear=True):
+        worktree = os.path.realpath(os.getcwd())
+        _bind_test_lock(
+            issue_number=196,
+            branch_name="feat/issue-196-mutations",
+            remote="prgs",
+            worktree_path=worktree,
+        )
+        with patch.dict(os.environ, self._create_pr_env(), clear=True):
             for term in ("equivalent to #196", "related to #196", "same as #196"):
                 with self.assertRaises(ValueError) as ctx:
-                    gitea_create_pr(title=f"feat: X {term}", head="feat/issue-196-mutations", remote="prgs")
+                    gitea_create_pr(
+                        title=f"feat: X {term}",
+                        head="feat/issue-196-mutations",
+                        remote="prgs",
+                        worktree_path=worktree,
+                    )
                 self.assertIn("contains forbidden term", str(ctx.exception))
 
     @patch("mcp_server.role_session_router.check_author_mutation_after_reviewer_stop",
            return_value=(True, []))
     @patch("mcp_server.get_auth_header", return_value=FAKE_AUTH)
     def test_create_pr_missing_closes_ref_fails(self, _auth, _role):
-        with open(ISSUE_LOCK_FILE, "w", encoding="utf-8") as f:
-            json.dump(_sample_issue_lock(
-                issue_number=196, branch_name="feat/issue-196-mutations"), f)
-        with patch.dict(os.environ, CREATE_PR_ENV, clear=True):
+        worktree = os.path.realpath(os.getcwd())
+        _bind_test_lock(
+            issue_number=196,
+            branch_name="feat/issue-196-mutations",
+            remote="prgs",
+            worktree_path=worktree,
+        )
+        with patch.dict(os.environ, self._create_pr_env(), clear=True):
             with self.assertRaises(ValueError) as ctx:
-                gitea_create_pr(title="feat: X refs #196", head="feat/issue-196-mutations", remote="prgs")
+                gitea_create_pr(
+                    title="feat: X refs #196",
+                    head="feat/issue-196-mutations",
+                    remote="prgs",
+                    worktree_path=worktree,
+                )
         self.assertIn("must contain 'Closes #196' or 'Fixes #196' exactly", str(ctx.exception))
 
     @patch("mcp_server.role_session_router.check_author_mutation_after_reviewer_stop",
@@ -3297,13 +3525,13 @@ class TestIssueLocking(unittest.TestCase):
     @patch("mcp_server.get_auth_header", return_value=FAKE_AUTH)
     def test_create_pr_worktree_mismatch_fails(self, _auth, _role):
         scratch = os.path.realpath("/tmp/gitea-tools-author-scratch/issue-249-pr")
-        with open(ISSUE_LOCK_FILE, "w", encoding="utf-8") as f:
-            json.dump(_sample_issue_lock(
-                issue_number=249,
-                branch_name="feat/issue-249-issue-lock-scratch-worktree",
-                worktree_path=scratch,
-            ), f)
-        with patch.dict(os.environ, CREATE_PR_ENV, clear=True):
+        _bind_test_lock(
+            issue_number=249,
+            branch_name="feat/issue-249-issue-lock-scratch-worktree",
+            worktree_path=scratch,
+            remote="prgs",
+        )
+        with patch.dict(os.environ, self._create_pr_env(), clear=True):
             with self.assertRaises(ValueError) as ctx:
                 gitea_create_pr(
                     title="feat: lock scratch worktree Closes #249",
@@ -3317,22 +3545,35 @@ class TestIssueLocking(unittest.TestCase):
            return_value=(True, []))
     @patch("mcp_server.get_auth_header", return_value=FAKE_AUTH)
     def test_create_pr_manual_lock_seed_blocked(self, _auth, _role):
-        with open(ISSUE_LOCK_FILE, "w", encoding="utf-8") as f:
-            json.dump(
+        worktree = os.path.realpath(os.getcwd())
+        with tempfile.TemporaryDirectory() as lock_dir:
+            env = {**self._create_pr_env(), "GITEA_ISSUE_LOCK_DIR": lock_dir}
+            with patch.dict(os.environ, env, clear=True):
+                issue_lock_store.save_lock_file(
+                    issue_lock_store.lock_file_path(
+                        remote="prgs",
+                        org="Scaled-Tech-Consulting",
+                        repo=mcp_server.REMOTES["prgs"]["repo"],
+                        issue_number=447,
+                        lock_dir=lock_dir,
+                    ),
                 _sample_issue_lock(
                     issue_number=447,
                     branch_name="feat/issue-447-lock-provenance",
+                    remote="prgs",
+                    org="Scaled-Tech-Consulting",
+                    repo=mcp_server.REMOTES["prgs"]["repo"],
+                    worktree_path=worktree,
                     lock_provenance=None,
                 ),
-                f,
-            )
-        with patch.dict(os.environ, CREATE_PR_ENV, clear=True):
-            with self.assertRaises(RuntimeError) as ctx:
-                gitea_create_pr(
-                    title="feat: lock provenance Closes #447",
-                    head="feat/issue-447-lock-provenance",
-                    remote="prgs",
                 )
+                with self.assertRaises(RuntimeError) as ctx:
+                    gitea_create_pr(
+                        title="feat: lock provenance Closes #447",
+                        head="feat/issue-447-lock-provenance",
+                        remote="prgs",
+                        worktree_path=worktree,
+                    )
         self.assertIn("lock provenance", str(ctx.exception).lower())
 
     @patch("mcp_server.api_request")
@@ -3342,13 +3583,13 @@ class TestIssueLocking(unittest.TestCase):
     def test_create_pr_honors_scratch_worktree_lock(self, _auth, _role, mock_api):
         scratch = os.path.realpath("/tmp/gitea-tools-author-scratch/issue-249-e2e")
         mock_api.return_value = {"number": 250, "html_url": "https://example/pr/250"}
-        with open(ISSUE_LOCK_FILE, "w", encoding="utf-8") as f:
-            json.dump(_sample_issue_lock(
-                issue_number=249,
-                branch_name="feat/issue-249-issue-lock-scratch-worktree",
-                worktree_path=scratch,
-            ), f)
-        with patch.dict(os.environ, CREATE_PR_ENV, clear=True):
+        _bind_test_lock(
+            issue_number=249,
+            branch_name="feat/issue-249-issue-lock-scratch-worktree",
+            worktree_path=scratch,
+            remote="prgs",
+        )
+        with patch.dict(os.environ, self._create_pr_env(), clear=True):
             res = gitea_create_pr(
                 title="feat: issue-lock scratch worktree Closes #249",
                 head="feat/issue-249-issue-lock-scratch-worktree",

tests/test_pr_queue_inventory.py

@@ -156,9 +156,22 @@ class TestPRQueueInventory(unittest.TestCase):
         ]
 
         from mcp_server import init_review_decision_lock, gitea_mark_final_review_decision
-        init_review_decision_lock("prgs", "review_pr")
-        gitea_mark_final_review_decision(1, "approve", remote="prgs")
-        result = gitea_review_pr(pr_number=1, event="APPROVE", remote="prgs", final_review_decision_ready=True)
+        from tests.test_mcp_server import _install_owned_reviewer_lease
+        import reviewer_pr_lease
+
+        with patch("mcp_server._authenticated_username", return_value="reviewer1"):
+            init_review_decision_lock("prgs", "review_pr")
+            gitea_mark_final_review_decision(1, "approve", remote="prgs")
+            lease_patch = _install_owned_reviewer_lease(
+                1, head_sha="abc1", session_id="inventory-review-lease",
+            )
+            lease_patch.start()
+            self.addCleanup(lease_patch.stop)
+            self.addCleanup(reviewer_pr_lease.clear_session_lease)
+            result = gitea_review_pr(
+                pr_number=1, event="APPROVE", remote="prgs",
+                final_review_decision_ready=True,
+            )
         self.assertTrue(result["success"])
         self.assertIn("=== PR Queue Inventory ===", result["message"])
         self.assertIn("Repository:", result["message"])

tests/test_reviewer_pr_lease.py

@@ -0,0 +1,193 @@
+"""Tests for per-PR reviewer leases (#407)."""
+
+import sys
+import unittest
+from datetime import datetime, timedelta, timezone
+from unittest.mock import patch
+
+sys.path.insert(0, str(__import__("pathlib").Path(__file__).resolve().parent.parent))
+
+import reviewer_pr_lease as leases
+
+
+def _lease_comment(
+    pr_number: int,
+    session_id: str,
+    *,
+    phase: str = "claimed",
+    minutes_ago: int = 0,
+    candidate_head: str = "a" * 40,
+) -> dict:
+    now = datetime.now(timezone.utc) - timedelta(minutes=minutes_ago)
+    body = leases.format_lease_body(
+        repo="Scaled-Tech-Consulting/Gitea-Tools",
+        pr_number=pr_number,
+        issue_number=295,
+        reviewer_identity="rev1",
+        profile="prgs-reviewer",
+        session_id=session_id,
+        worktree="branches/review-pr382",
+        phase=phase,
+        candidate_head=candidate_head,
+        target_branch="master",
+        target_branch_sha="b" * 40,
+        last_activity=now,
+    )
+    return {"id": 1, "body": body, "user": {"login": "rev1"}}
+
+
+class TestReviewerLeaseAcquire(unittest.TestCase):
+    def setUp(self):
+        leases.clear_session_lease()
+
+    def test_two_reviewers_cannot_lease_same_pr(self):
+        comments = [_lease_comment(382, "session-a")]
+        result = leases.assess_acquire_lease(
+            comments,
+            pr_number=382,
+            reviewer_identity="rev2",
+            profile="prgs-reviewer",
+            session_id="session-b",
+            repo="Scaled-Tech-Consulting/Gitea-Tools",
+            issue_number=295,
+            worktree="branches/review-pr382-b",
+            candidate_head="c" * 40,
+            target_branch="master",
+            target_branch_sha="d" * 40,
+        )
+        self.assertFalse(result["acquire_allowed"])
+        self.assertTrue(any("already has active" in r for r in result["reasons"]))
+
+    def test_two_reviewers_can_lease_different_prs(self):
+        comments = [_lease_comment(382, "session-a")]
+        result = leases.assess_acquire_lease(
+            comments,
+            pr_number=383,
+            reviewer_identity="rev2",
+            profile="prgs-reviewer",
+            session_id="session-b",
+            repo="Scaled-Tech-Consulting/Gitea-Tools",
+            issue_number=296,
+            worktree="branches/review-pr383",
+            candidate_head="c" * 40,
+            target_branch="master",
+            target_branch_sha="d" * 40,
+        )
+        self.assertTrue(result["acquire_allowed"])
+        self.assertIsNotNone(result["lease_body"])
+
+
+class TestReviewerLeaseFreshness(unittest.TestCase):
+    def test_stale_warning_after_30_minutes(self):
+        lease = leases.parse_lease_comment(
+            _lease_comment(382, "session-a", minutes_ago=35)["body"]
+        )
+        self.assertEqual(
+            leases.classify_lease_freshness(lease),
+            "stale_warning",
+        )
+
+    def test_reclaimable_after_60_minutes(self):
+        lease = leases.parse_lease_comment(
+            _lease_comment(382, "session-a", minutes_ago=65)["body"]
+        )
+        self.assertEqual(
+            leases.classify_lease_freshness(lease),
+            "reclaimable",
+        )
+
+
+class TestReviewerLeaseMutationGate(unittest.TestCase):
+    def setUp(self):
+        leases.clear_session_lease()
+
+    def test_reviewer_without_lease_cannot_mutate(self):
+        head = "f" * 40
+        comments = [_lease_comment(382, "other-session", candidate_head=head)]
+        result = leases.assess_mutation_lease_gate(
+            pr_number=382,
+            comments=comments,
+            reviewer_identity="rev1",
+            session_id="my-session",
+            mutation="approve",
+            live_head_sha=head,
+            pinned_head_sha=head,
+        )
+        self.assertTrue(result["block"])
+
+    def test_owned_lease_allows_mutation(self):
+        head = "f" * 40
+        comments = [_lease_comment(382, "my-session", candidate_head=head)]
+        leases.record_session_lease({
+            "pr_number": 382,
+            "session_id": "my-session",
+            "candidate_head": head,
+            "target_branch": "master",
+        })
+        result = leases.assess_mutation_lease_gate(
+            pr_number=382,
+            comments=comments,
+            reviewer_identity="rev1",
+            session_id="my-session",
+            mutation="approve",
+            live_head_sha=head,
+            pinned_head_sha=head,
+        )
+        self.assertFalse(result["block"])
+
+    def test_head_change_invalidates_lease(self):
+        reviewed = "f" * 40
+        live = "e" * 40
+        comments = [_lease_comment(382, "my-session", candidate_head=reviewed)]
+        leases.record_session_lease({
+            "pr_number": 382,
+            "session_id": "my-session",
+            "candidate_head": reviewed,
+        })
+        result = leases.assess_mutation_lease_gate(
+            pr_number=382,
+            comments=comments,
+            reviewer_identity="rev1",
+            session_id="my-session",
+            mutation="merge",
+            live_head_sha=live,
+            pinned_head_sha=reviewed,
+        )
+        self.assertTrue(result["block"])
+        self.assertTrue(any("head" in r.lower() for r in result["reasons"]))
+
+
+class TestReviewerLeaseMcpGate(unittest.TestCase):
+    def setUp(self):
+        leases.clear_session_lease()
+        patch("mcp_server.verify_preflight_purity").start()
+        patch("gitea_audit.audit_enabled", return_value=False).start()
+        mcp_server = __import__("mcp_server")
+        mcp_server._IDENTITY_CACHE.clear()
+        mcp_server.init_review_decision_lock("prgs", "review_pr")
+        mcp_server.record_preflight_check("whoami")
+        mcp_server.record_preflight_check("capability", "reviewer")
+
+    def tearDown(self):
+        patch.stopall()
+        leases.clear_session_lease()
+
+    def test_reviewer_pr_lease_gate_helper_blocks_without_session(self):
+        import mcp_server
+        head = "a" * 40
+        with patch("mcp_server._fetch_pr_comments", return_value=[]):
+            reasons = mcp_server._reviewer_pr_lease_gate(
+                pr_number=382,
+                remote="prgs",
+                host=None,
+                org=None,
+                repo=None,
+                mutation="approve",
+                live_head_sha=head,
+                pinned_head_sha=head,
+            )
+        self.assertTrue(any("lease" in r.lower() for r in reasons))
+
+
+if __name__ == "__main__":
+    unittest.main()

tests/test_worktrees.py

@@ -20,33 +20,50 @@ def run(script, *args):
             branch = arg
             break
 
-    lock_file = Path("/tmp/gitea_issue_lock.json")
-    created_lock = False
+    lock_dir_ctx = None
+    extra_env = os.environ.copy()
     if script == "worktree-start" and branch:
         import re
-        import json
+        import tempfile
+        import issue_lock_store
+
         m = re.search(r"issue-(\d+)", branch)
         if not m:
             m = re.search(r"pr-(\d+)", branch)
         issue_num = int(m.group(1)) if m else 999
-        lock_file.write_text(json.dumps({
+        lock_dir_ctx = tempfile.TemporaryDirectory()
+        extra_env["GITEA_ISSUE_LOCK_DIR"] = lock_dir_ctx.name
+        record = {
             "issue_number": issue_num,
             "branch_name": branch,
             "remote": "prgs",
             "org": "Scaled-Tech-Consulting",
-            "repo": "Gitea-Tools"
-        }), encoding="utf-8")
-        created_lock = True
+            "repo": "Gitea-Tools",
+            "worktree_path": "/tmp/test-worktree",
+            "work_lease": {
+                "operation_type": "author_issue_work",
+                "expires_at": "2999-01-01T00:00:00Z",
+            },
+        }
+        path = issue_lock_store.lock_file_path(
+            remote="prgs",
+            org="Scaled-Tech-Consulting",
+            repo="Gitea-Tools",
+            issue_number=issue_num,
+            lock_dir=lock_dir_ctx.name,
+        )
+        issue_lock_store.save_lock_file(path, record)
 
     try:
         proc = subprocess.run(
             ["bash", str(SCRIPTS / script), *args],
             capture_output=True, text=True, cwd=str(REPO),
+            env=extra_env,
         )
         return proc.returncode, proc.stdout, proc.stderr
     finally:
-        if created_lock and lock_file.exists():
-            lock_file.unlink()
+        if lock_dir_ctx is not None:
+            lock_dir_ctx.cleanup()
 
 
 class TestWorktreeStart(unittest.TestCase):