resolve conflicts for PR #464

Replace read-modify-write on the global /tmp/gitea_issue_lock.json pointer with
atomic per-issue locks under GITEA_ISSUE_LOCK_DIR using flock serialization,
PID/session metadata, fail-closed stale recovery, and pre-mutation freshness
re-checks in gitea_create_pr. Queue inventory now surfaces live_issue_locks.

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

docs/llm-workflow-runbooks.md

@@ -274,12 +274,35 @@ 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,
+acquires an atomic per-issue lock under `GITEA_ISSUE_LOCK_DIR` (default
+`/tmp/gitea_issue_locks/`) and updates the legacy session pointer at
+`GITEA_ISSUE_LOCK_FILE` only when safe. The payload records issue number,
+branch, repo scope, worktree path, claimant identity/profile, PID, session id,
 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.
+same-issue/same-operation lease blocks duplicate work. An expired or dead-PID
+lease still blocks takeover until a recovery review records why the prior work
+is abandoned, completed, or unsafe to continue.
+
+Author/reviewer/reconciler final reports must include **Issue lock proof** with:
+lock acquired, lock owner, lock freshness, no competing live lock (when
+applicable), and whether the lock was released or intentionally retained.
+`gitea_lock_issue` returns a canonical `lock_proof` string for handoffs.
+`gitea_list_claim_inventory` exposes `live_issue_locks` for queue visibility.
+
+**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
+shared state and manual writes can clobber another session's live lease. Use
+`sanctioned recovery` instead:
+
+1. `gitea_lock_issue` on a clean `branches/` worktree (normal path).
+2. Own-branch adoption via #442 when the issue's exact branch is already pushed.
+3. Operator override only when explicitly authorized — record
+   `External-state mutations` and `operator override proof` in the final report.
+
+`gitea_create_pr` rejects lock files that lack sanctioned `lock_provenance`
+metadata. Final-report validation blocks handoffs that hide lock read/write/delete
+under `External-state mutations: none` or mix author PR creation with reviewer
+approval in one run. See also #438 (global lock redesign).
 
 Remote branches matching the issue number are also treated as active work unless
 the recovery review proves the branch is abandoned or superseded. Never delete

final_report_validator.py

@@ -11,6 +11,7 @@ import inspect
 import re
 from typing import Any, Callable
 
+import issue_lock_provenance
 from review_proofs import (
     HANDOFF_HEADING,
     assess_controller_handoff,
@@ -870,6 +871,54 @@ def _rule_reviewer_mutation_ledger(
     )
 
 
+def _rule_shared_issue_lock_external_state(report_text: str) -> list[dict[str, str]]:
+    result = issue_lock_provenance.assess_issue_lock_external_state_report(report_text)
+    if result.get("proven"):
+        return []
+    return _findings_from_reasons(
+        "shared.issue_lock_external_state",
+        result.get("reasons") or [],
+        field="External-state mutations",
+        severity="block",
+        safe_next_action=(
+            "disclose gitea_issue_lock.json read/write/delete under "
+            "External-state mutations; never claim none after lock seeding"
+        ),
+    )
+
+
+def _rule_shared_manual_lock_pr_override(report_text: str) -> list[dict[str, str]]:
+    result = issue_lock_provenance.assess_manual_lock_pr_without_override(report_text)
+    if result.get("proven"):
+        return []
+    return _findings_from_reasons(
+        "shared.manual_lock_pr_override",
+        result.get("reasons") or [],
+        field="External-state mutations",
+        severity="block",
+        safe_next_action=(
+            "use gitea_lock_issue or #442 adoption instead of manual lock seeding; "
+            "if operator override was authorized, cite override proof"
+        ),
+    )
+
+
+def _rule_shared_author_reviewer_same_run(report_text: str) -> list[dict[str, str]]:
+    result = issue_lock_provenance.assess_author_reviewer_same_run_report(report_text)
+    if result.get("proven"):
+        return []
+    return _findings_from_reasons(
+        "shared.author_reviewer_same_run",
+        result.get("reasons") or [],
+        field="Review mutations",
+        severity="block",
+        safe_next_action=(
+            "split author PR creation and reviewer approval across separate "
+            "sessions and handoffs"
+        ),
+    )
+
+
 def _rule_reviewer_review_mutation(
     report_text: str,
     *,
@@ -889,10 +938,17 @@ def _rule_reviewer_review_mutation(
     )
 
 
+_SHARED_ISSUE_LOCK_RULES = (
+    _rule_shared_issue_lock_external_state,
+    _rule_shared_manual_lock_pr_override,
+    _rule_shared_author_reviewer_same_run,
+)
+
 _RULES_BY_TASK: dict[str, list[Callable[..., list[dict[str, str]]]]] = {
     "review_pr": [
         _rule_shared_controller_handoff,
         _rule_shared_email_disclosure,
+        *_SHARED_ISSUE_LOCK_RULES,
         _rule_reviewer_legacy_workspace_mutations,
         _rule_reviewer_vague_mutations_none,
         _rule_reviewer_mutation_categories,
@@ -913,6 +969,7 @@ _RULES_BY_TASK: dict[str, list[Callable[..., list[dict[str, str]]]]] = {
     "reconcile_already_landed": [
         _rule_reconcile_controller_handoff,
         _rule_shared_email_disclosure,
+        *_SHARED_ISSUE_LOCK_RULES,
         _rule_reconcile_stale_author_fields,
         _rule_reconcile_eligible_reviewed,
         _rule_reconcile_linked_issue_live,
@@ -924,25 +981,30 @@ _RULES_BY_TASK: dict[str, list[Callable[..., list[dict[str, str]]]]] = {
     "author_issue": [
         _rule_shared_controller_handoff,
         _rule_shared_email_disclosure,
+        *_SHARED_ISSUE_LOCK_RULES,
         _rule_reviewer_vague_mutations_none,
     ],
     "work_issue": [
         _rule_shared_controller_handoff,
         _rule_shared_email_disclosure,
+        *_SHARED_ISSUE_LOCK_RULES,
         _rule_reviewer_vague_mutations_none,
     ],
     "issue_filing": [
         _rule_shared_controller_handoff,
         _rule_shared_email_disclosure,
+        *_SHARED_ISSUE_LOCK_RULES,
     ],
     "inventory": [
         _rule_shared_controller_handoff,
         _rule_shared_email_disclosure,
+        *_SHARED_ISSUE_LOCK_RULES,
         _rule_reconcile_pagination_proof,
     ],
     "issue_selection": [
         _rule_shared_controller_handoff,
         _rule_shared_email_disclosure,
+        *_SHARED_ISSUE_LOCK_RULES,
     ],
 }
 

gitea_mcp_server.py

@@ -538,9 +538,12 @@ import task_capability_map  # noqa: E402
 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 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 merged_cleanup_reconcile  # noqa: E402
 import reconciler_profile  # noqa: E402
 import reconciliation_workflow  # noqa: E402
@@ -582,14 +585,22 @@ def _parse_work_lease_timestamp(value: str | None) -> datetime | None:
 
 
 def _load_existing_issue_lock() -> dict | None:
-    if not os.path.exists(ISSUE_LOCK_FILE):
-        return None
-    try:
-        with open(ISSUE_LOCK_FILE, 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.read_lock_file(ISSUE_LOCK_FILE)
+
+
+def _load_issue_lock_for_scope(
+    *,
+    issue_number: int,
+    remote: str,
+    org: str,
+    repo: str,
+) -> dict | None:
+    return issue_lock_store.resolve_lock_for_issue(
+        issue_number=issue_number,
+        remote=remote,
+        org=org,
+        repo=repo,
+    ) or _load_existing_issue_lock()
 
 
 def _work_lease_claimant(host: str | None) -> dict:
@@ -679,6 +690,119 @@ def _branch_entry_name(branch: dict | str) -> str:
     return str(branch.get("name") or branch.get("ref") or "")
 
 
+def _live_fetch_issue_duplicate_context(
+    h: str,
+    o: str,
+    r: str,
+    auth: str,
+    issue_number: int,
+) -> tuple[list[dict], list[str], dict]:
+    """Live open PRs, remote branch names, and claim state for one issue."""
+    base = repo_api_url(h, o, r)
+    open_prs = api_get_all(f"{base}/pulls?state=open", auth)
+    branches = api_get_all(f"{base}/branches", auth)
+    branch_names = [_branch_entry_name(b) for b in branches]
+    issue = api_request("GET", f"{base}/issues/{issue_number}", auth) or {}
+    comments = api_request(
+        "GET", f"{base}/issues/{issue_number}/comments", auth
+    ) or []
+    claim_entry = issue_claim_heartbeat.classify_issue_claim(
+        issue=issue,
+        comments=comments,
+        open_prs=open_prs,
+        branch_names=branch_names,
+    )
+    return open_prs, branch_names, claim_entry
+
+
+# Injectable duplicate-work context fetcher (#400). Production uses the live
+# Gitea API path above; unit tests patch this symbol instead of hitting the
+# network.
+issue_duplicate_context_fetcher = _live_fetch_issue_duplicate_context
+
+
+def _collect_issue_duplicate_context(
+    h: str,
+    o: str,
+    r: str,
+    auth: str,
+    issue_number: int,
+) -> tuple[list[dict], list[str], dict]:
+    return issue_duplicate_context_fetcher(h, o, r, auth, issue_number)
+
+
+def _assess_issue_duplicate_gate(
+    issue_number: int,
+    *,
+    h: str,
+    o: str,
+    r: str,
+    auth: str,
+    locked_branch: str | None = None,
+    phase: str,
+) -> dict:
+    open_prs, branch_names, claim_entry = _collect_issue_duplicate_context(
+        h, o, r, auth, issue_number
+    )
+    return issue_work_duplicate_gate.assess_work_issue_duplicate_gate(
+        issue_number,
+        open_prs=open_prs,
+        branch_names=branch_names,
+        claim_entry=claim_entry,
+        locked_branch=locked_branch,
+        phase=phase,
+    )
+
+
+def _duplicate_gate_block_response(gate: dict, **extra) -> dict:
+    out = {
+        "success": False,
+        "performed": False,
+        "reasons": list(gate.get("reasons") or []),
+        "duplicate_gate": gate,
+        "safe_next_action": gate.get("safe_next_action"),
+    }
+    out.update(extra)
+    return out
+
+
+def _enforce_locked_issue_duplicate_recheck(
+    remote: str,
+    phase: str,
+    *,
+    host: str | None = None,
+    org: str | None = None,
+    repo: str | None = None,
+) -> dict | None:
+    """Re-check duplicate-work gates for the locked issue (#400)."""
+    lock_data = _load_existing_issue_lock()
+    if not lock_data:
+        return None
+    issue_number = int(lock_data.get("issue_number") or 0)
+    locked_branch = lock_data.get("branch_name")
+    if not issue_number:
+        return None
+    h, o, r = _resolve(
+        remote or lock_data.get("remote") or "dadeschools",
+        host or lock_data.get("host"),
+        org or lock_data.get("org"),
+        repo or lock_data.get("repo"),
+    )
+    auth = _auth(h)
+    gate = _assess_issue_duplicate_gate(
+        issue_number,
+        h=h,
+        o=o,
+        r=r,
+        auth=auth,
+        locked_branch=locked_branch,
+        phase=phase,
+    )
+    if gate.get("block"):
+        return gate
+    return 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
@@ -1126,8 +1250,14 @@ def gitea_lock_issue(
     resolved_worktree = issue_lock_worktree.resolve_author_worktree_path(
         worktree_path, PROJECT_ROOT
     )
+    h, o, r = _resolve(remote, host, org, repo)
     active_lease_block = _active_work_lease_block(
-        _load_existing_issue_lock(),
+        _load_issue_lock_for_scope(
+            issue_number=issue_number,
+            remote=remote,
+            org=o,
+            repo=r,
+        ),
         issue_number=issue_number,
         branch_name=branch_name,
         worktree_path=resolved_worktree,
@@ -1151,48 +1281,20 @@ def gitea_lock_issue(
             issue_lock_worktree.format_issue_lock_worktree_error(lock_assessment)
         )
 
-    # 2. Check if the issue already has an open PR (reuse protection)
-    h, o, r = _resolve(remote, host, org, repo)
     auth = _auth(h)
-    url = f"{repo_api_url(h, o, r)}/pulls?state=open"
-
-    try:
-        prs = api_get_all(url, auth)
-    except Exception as e:
-        raise RuntimeError(f"Could not list open PRs to verify issue lock: {e}")
-
-    for pr in prs:
-        pr_head = pr.get("head", {}).get("ref", "")
-        pr_title = pr.get("title", "")
-        pr_body = pr.get("body", "")
-
-        if expected_pattern in pr_head:
-            raise ValueError(
-                f"Issue #{issue_number} is already tied to an open PR (PR #{pr.get('number')}, branch '{pr_head}') (fail closed)"
-            )
-
-        patterns = [
-            f"closes #{issue_number}",
-            f"fixes #{issue_number}",
-        ]
-        text_to_check = f"{pr_title} {pr_body}".lower()
-        if any(p in text_to_check for p in patterns):
-            raise ValueError(
-                f"Issue #{issue_number} is already tied to an open PR (PR #{pr.get('number')}) via Closes/Fixes reference (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}")
-    for branch in branches:
-        name = _branch_entry_name(branch)
-        if expected_pattern in name:
-            raise ValueError(
-                f"Issue #{issue_number} already has matching branch '{name}' "
-                "(fail closed)"
+    duplicate_gate = _assess_issue_duplicate_gate(
+        issue_number,
+        h=h,
+        o=o,
+        r=r,
+        auth=auth,
+        locked_branch=branch_name,
+        phase=issue_work_duplicate_gate.PHASE_LOCK,
     )
+    if duplicate_gate.get("block"):
+        raise ValueError("; ".join(duplicate_gate.get("reasons") or [
+            f"duplicate work gate blocked issue #{issue_number} (fail closed)"
+        ]))
 
     work_lease = _build_author_issue_work_lease(
         issue_number=issue_number,
@@ -1200,25 +1302,41 @@ def gitea_lock_issue(
         worktree_path=resolved_worktree,
         host=h,
     )
-    data = {
-        "issue_number": issue_number,
-        "branch_name": branch_name,
-        "remote": remote,
-        "org": o,
-        "repo": r,
-        "worktree_path": resolved_worktree,
-        "work_lease": work_lease,
-    }
-
+    lock_provenance = issue_lock_provenance.build_sanctioned_lock_provenance(
+        tool="gitea_lock_issue",
+        claimant=work_lease.get("claimant"),
+    )
     try:
-        with open(ISSUE_LOCK_FILE, "w", encoding="utf-8") as f:
-            json.dump(data, f)
+        acquisition = issue_lock_store.acquire_issue_lock(
+            issue_number=issue_number,
+            branch_name=branch_name,
+            remote=remote,
+            org=o,
+            repo=r,
+            worktree_path=resolved_worktree,
+            work_lease=work_lease,
+            claimant=_work_lease_claimant(h),
+            lock_provenance=lock_provenance,
+        )
+    except RuntimeError:
+        raise
     except Exception as e:
-        raise RuntimeError(f"Could not write issue lock file: {e}")
+        raise RuntimeError(f"Could not acquire issue lock: {e}") from e
 
     agent_artifacts = agent_temp_artifacts.find_agent_temp_artifacts_from_porcelain(
         git_state.get("porcelain_status") or ""
     )
+    competing = [
+        entry
+        for entry in issue_lock_store.list_live_locks()
+        if entry.get("issue_number") != issue_number
+    ]
+    lock_proof = issue_lock_store.format_lock_proof(
+        acquisition["record"],
+        freshness=acquisition["freshness"],
+        competing_live_locks=competing,
+        released=False,
+    )
     result = {
         "success": True,
         "message": (
@@ -1229,6 +1347,11 @@ def gitea_lock_issue(
         "branch_name": branch_name,
         "worktree_path": resolved_worktree,
         "work_lease": work_lease,
+        "lock_path": acquisition["lock_path"],
+        "session_id": acquisition["session_id"],
+        "lock_freshness": acquisition["freshness"],
+        "legacy_pointer": acquisition["legacy_pointer"],
+        "lock_proof": lock_proof,
     }
     if agent_artifacts:
         result["warnings"] = [
@@ -1238,6 +1361,39 @@ def gitea_lock_issue(
     return result
 
 
+@mcp.tool()
+def gitea_assess_work_issue_duplicate(
+    issue_number: int,
+    branch_name: str | None = None,
+    phase: str = issue_work_duplicate_gate.PHASE_LOCK,
+    remote: str = "dadeschools",
+    host: str | None = None,
+    org: str | None = None,
+    repo: str | None = None,
+) -> dict:
+    """Read-only duplicate-work gate for author sessions before mutations (#400)."""
+    read_block = _profile_operation_gate("gitea.read")
+    if read_block:
+        return {
+            "success": False,
+            "performed": False,
+            "reasons": read_block,
+            "permission_report": _permission_block_report("gitea.read"),
+        }
+    h, o, r = _resolve(remote, host, org, repo)
+    auth = _auth(h)
+    gate = _assess_issue_duplicate_gate(
+        issue_number,
+        h=h,
+        o=o,
+        r=r,
+        auth=auth,
+        locked_branch=branch_name,
+        phase=phase,
+    )
+    return {"success": not gate.get("block"), **gate}
+
+
 @mcp.tool()
 def gitea_create_pr(
     title: str,
@@ -1288,15 +1444,27 @@ 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):
+    # ── Issue Lock Validation (Issue #194 / #196 / #438) ──
+    lock_data = _load_existing_issue_lock()
+    if not lock_data:
         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)")
+    scoped_lock = issue_lock_store.resolve_lock_for_issue(
+        issue_number=int(lock_data.get("issue_number") or 0),
+        remote=lock_data.get("remote"),
+        org=lock_data.get("org"),
+        repo=lock_data.get("repo"),
+    )
+    if scoped_lock:
+        lock_data = scoped_lock
+
+    lock_provenance_check = issue_lock_provenance.assess_lock_file_for_create_pr(
+        lock_data
+    )
+    if lock_provenance_check["block"]:
+        raise RuntimeError(
+            issue_lock_provenance.format_lock_provenance_error(lock_provenance_check)
+        )
 
     locked_issue = lock_data.get("issue_number")
     locked_branch = lock_data.get("branch_name")
@@ -1313,6 +1481,10 @@ def gitea_create_pr(
             f"PR head branch '{head}' does not match locked branch '{locked_branch}' (fail closed)"
         )
 
+    ownership = issue_lock_store.verify_lock_for_mutation(lock_data)
+    if ownership["block"]:
+        raise ValueError(ownership["reasons"][0])
+
     # Check for forbidden terms anywhere in title/body
     forbidden_terms = ["equivalent", "related", "same as"]
     text_to_check = f"{title} {body}".lower()
@@ -1329,6 +1501,21 @@ def gitea_create_pr(
             f"PR title or body must contain 'Closes #{locked_issue}' or 'Fixes #{locked_issue}' exactly to ensure durable tracking (fail closed)"
         )
 
+    duplicate_block = _enforce_locked_issue_duplicate_recheck(
+        remote,
+        issue_work_duplicate_gate.PHASE_CREATE_PR,
+        host=host,
+        org=org,
+        repo=repo,
+    )
+    if duplicate_block:
+        return _duplicate_gate_block_response(
+            duplicate_block,
+            number=None,
+            issue_number=locked_issue,
+            branch_name=locked_branch,
+        )
+
     auth = _auth(h)
     url = f"{repo_api_url(h, o, r)}/pulls"
     payload = {"title": title, "body": body, "head": head, "base": base}
@@ -2792,13 +2979,7 @@ 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 = _load_existing_issue_lock() or {}
 
     locked_worktree = lock_data.get("worktree_path")
     if locked_worktree:
@@ -2933,6 +3114,20 @@ def gitea_commit_files(
     if blocked:
         return blocked
 
+    duplicate_block = _enforce_locked_issue_duplicate_recheck(
+        remote,
+        issue_work_duplicate_gate.PHASE_COMMIT,
+        host=host,
+        org=org,
+        repo=repo,
+    )
+    if duplicate_block:
+        return _duplicate_gate_block_response(
+            duplicate_block,
+            commit="",
+            branch="",
+        )
+
     verify_preflight_purity(remote)
     processed_files, source_proofs = _prepare_commit_payload_files(files)
 
@@ -6169,6 +6364,15 @@ def gitea_reconcile_issue_claims(
         heartbeat_lease_minutes=heartbeat_lease_minutes,
         reclaim_after_minutes=reclaim_after_minutes,
     )
+    live_locks = issue_lock_store.list_live_locks()
+    inventory["live_issue_locks"] = live_locks
+    inventory["live_issue_lock_numbers"] = sorted(
+        {
+            int(entry["issue_number"])
+            for entry in live_locks
+            if entry.get("issue_number") is not None
+        }
+    )
     inventory["cleanup_plan"] = issue_claim_heartbeat.build_cleanup_plan(inventory)
     inventory["success"] = True
     inventory["performed"] = False

issue_lock_provenance.py

@@ -0,0 +1,269 @@
+"""Issue-lock provenance and external-state disclosure (#447).
+
+Sanctioned locks are written only by ``gitea_lock_issue`` (or adoption recovery
+#442). Manual seeding of ``/tmp/gitea_issue_lock.json`` is unsafe and must be
+blocked at PR creation unless explicit operator override proof is recorded.
+"""
+
+from __future__ import annotations
+
+import os
+import re
+from datetime import datetime, timezone
+
+ISSUE_LOCK_FILE = os.environ.get("GITEA_ISSUE_LOCK_FILE", "/tmp/gitea_issue_lock.json")
+
+SOURCE_LOCK_ISSUE = "gitea_lock_issue"
+SOURCE_LOCK_ADOPTION = "gitea_lock_issue_adoption"
+SOURCE_OPERATOR_OVERRIDE = "operator_override"
+
+SANCTIONED_LOCK_SOURCES = frozenset({
+    SOURCE_LOCK_ISSUE,
+    SOURCE_LOCK_ADOPTION,
+    SOURCE_OPERATOR_OVERRIDE,
+})
+
+_OPERATOR_OVERRIDE_ENV = "GITEA_ISSUE_LOCK_OPERATOR_OVERRIDE"
+
+_ISSUE_LOCK_PATH_RE = re.compile(
+    r"(?:/tmp/)?gitea_issue_lock\.json",
+    re.IGNORECASE,
+)
+_LOCK_SEED_RE = re.compile(
+    r"(?:seed(?:ed|ing)?|restor(?:e|ed|ing)|wrote|written|write|programmatically|"
+    r"hand[- ]forg|manual(?:ly)?).{0,80}gitea_issue_lock",
+    re.IGNORECASE | re.DOTALL,
+)
+_LOCK_REMOVE_RE = re.compile(
+    r"(?:\brm\b|remove|deleted?|unlink).{0,80}gitea_issue_lock",
+    re.IGNORECASE | re.DOTALL,
+)
+_LOCK_READ_RE = re.compile(
+    r"(?:read|loaded?|parsed?).{0,80}gitea_issue_lock",
+    re.IGNORECASE | re.DOTALL,
+)
+_EXTERNAL_NONE_RE = re.compile(
+    r"external[- ]state mutations\s*:\s*none\b",
+    re.IGNORECASE,
+)
+_EXTERNAL_FIELD_RE = re.compile(
+    r"external[- ]state mutations\s*:\s*(.+)$",
+    re.IGNORECASE | re.MULTILINE,
+)
+_CLEANUP_ONLY_RE = re.compile(
+    r"cleanup mutations\s*:\s*(?:none|lock removed|removed issue lock)",
+    re.IGNORECASE,
+)
+_PR_CREATED_RE = re.compile(
+    r"(?:\bgitea_create_pr\b|PR\s*#\s*\d+\s+created|created\s+PR\s*#|opened\s+PR\s*#|"
+    r"PR\s+creation\s+(?:succeeded|complete))",
+    re.IGNORECASE,
+)
+_REVIEW_APPROVE_RE = re.compile(
+    r"(?:submitted\s+(?:['\"]approve['\"]|approve\s+review)|"
+    r"review decision\s*:\s*approve|approved\s+PR\s*#|gitea_review_pr.*approve)",
+    re.IGNORECASE,
+)
+_OVERRIDE_PROOF_RE = re.compile(
+    r"operator[- ]override\s+proof\s*:\s*(.+)$",
+    re.IGNORECASE | re.MULTILINE,
+)
+
+
+def _utc_now_iso() -> str:
+    return datetime.now(timezone.utc).strftime("%Y-%m-%dT%H:%M:%SZ")
+
+
+def build_sanctioned_lock_provenance(
+    *,
+    tool: str,
+    source: str = SOURCE_LOCK_ISSUE,
+    claimant: dict | None = None,
+    adoption: dict | None = None,
+) -> dict:
+    """Return provenance metadata stored with a sanctioned lock write."""
+    entry = {
+        "source": source,
+        "written_at": _utc_now_iso(),
+        "written_by_tool": tool,
+        "lock_file_path": ISSUE_LOCK_FILE,
+    }
+    if claimant:
+        entry["claimant"] = claimant
+    if adoption:
+        entry["adoption"] = adoption
+    return entry
+
+
+def operator_override_requested() -> bool:
+    return os.environ.get(_OPERATOR_OVERRIDE_ENV, "").strip().lower() in {
+        "1",
+        "true",
+        "yes",
+    }
+
+
+def build_operator_override_provenance(*, reason: str, claimant: dict | None = None) -> dict:
+    text = (reason or "").strip()
+    if not text:
+        raise ValueError(
+            "operator override requires a non-empty override reason (fail closed)"
+        )
+    entry = build_sanctioned_lock_provenance(
+        tool="operator_override",
+        source=SOURCE_OPERATOR_OVERRIDE,
+        claimant=claimant,
+    )
+    entry["override_reason"] = text
+    return entry
+
+
+def assess_lock_file_for_create_pr(lock_data: dict | None) -> dict:
+    """Fail closed when lock file lacks sanctioned provenance (#447)."""
+    data = lock_data if isinstance(lock_data, dict) else {}
+    reasons: list[str] = []
+    provenance = data.get("lock_provenance")
+    if not isinstance(provenance, dict):
+        reasons.append(
+            "issue lock file lacks sanctioned lock_provenance; manual seeding is "
+            "not a normal recovery path — call gitea_lock_issue or use #442 adoption"
+        )
+        return _provenance_result(False, reasons, provenance)
+
+    source = str(provenance.get("source") or "").strip()
+    if source not in SANCTIONED_LOCK_SOURCES:
+        reasons.append(
+            f"issue lock provenance source '{source or '(missing)'}' is not sanctioned"
+        )
+
+    if source == SOURCE_OPERATOR_OVERRIDE and not str(
+        provenance.get("override_reason") or ""
+    ).strip():
+        reasons.append(
+            "operator_override lock provenance requires override_reason proof"
+        )
+
+    if not data.get("work_lease"):
+        reasons.append("issue lock file missing work_lease metadata")
+
+    if not str(provenance.get("written_by_tool") or "").strip():
+        reasons.append("issue lock provenance missing written_by_tool")
+
+    proven = not reasons
+    return _provenance_result(proven, reasons, provenance)
+
+
+def _provenance_result(proven: bool, reasons: list[str], provenance: dict | None) -> dict:
+    return {
+        "proven": proven,
+        "block": not proven,
+        "reasons": reasons,
+        "lock_provenance": provenance,
+    }
+
+
+def format_lock_provenance_error(assessment: dict) -> str:
+    reasons = "; ".join(assessment.get("reasons") or ["unknown lock provenance violation"])
+    return f"Issue lock provenance guard (#447): {reasons} (fail closed)"
+
+
+def _lock_activity_detected(text: str) -> dict[str, bool]:
+    body = text or ""
+    return {
+        "seed_or_restore": bool(_LOCK_SEED_RE.search(body)),
+        "remove": bool(_LOCK_REMOVE_RE.search(body)),
+        "read": bool(_LOCK_READ_RE.search(body)),
+    }
+
+
+def _external_state_discloses_lock(text: str) -> bool:
+    match = _EXTERNAL_FIELD_RE.search(text or "")
+    if not match:
+        return False
+    value = (match.group(1) or "").strip().lower()
+    if value in {"", "none", "n/a"}:
+        return False
+    return "lock" in value or "gitea_issue_lock" in value or "issue-lock" in value
+
+
+def assess_issue_lock_external_state_report(report_text: str) -> dict:
+    """Require explicit external-state disclosure for issue-lock mutations (#447)."""
+    text = report_text or ""
+    activity = _lock_activity_detected(text)
+    if not any(activity.values()):
+        return {"proven": True, "block": False, "reasons": [], "activity": activity}
+
+    reasons: list[str] = []
+    disclosed = _external_state_discloses_lock(text)
+
+    if activity["seed_or_restore"] and _EXTERNAL_NONE_RE.search(text):
+        reasons.append(
+            "report mentions seeding/restoring gitea_issue_lock.json but claims "
+            "External-state mutations: none"
+        )
+    elif activity["seed_or_restore"] and not disclosed:
+        reasons.append(
+            "report mentions issue-lock file activity but External-state mutations "
+            "does not disclose read/write of gitea_issue_lock.json"
+        )
+
+    if activity["remove"]:
+        if _EXTERNAL_NONE_RE.search(text):
+            reasons.append(
+                "report mentions removing gitea_issue_lock.json but claims "
+                "External-state mutations: none"
+            )
+        elif not disclosed and _CLEANUP_ONLY_RE.search(text):
+            reasons.append(
+                "report removes issue lock but classifies it as cleanup only; "
+                "record under External-state mutations"
+            )
+        elif not disclosed:
+            reasons.append(
+                "report mentions deleting issue lock without External-state "
+                "mutation disclosure"
+            )
+
+    proven = not reasons
+    return {
+        "proven": proven,
+        "block": not proven,
+        "reasons": reasons,
+        "activity": activity,
+    }
+
+
+def assess_manual_lock_pr_without_override(report_text: str) -> dict:
+    """Block reports that created a PR via manual lock seed without override proof."""
+    text = report_text or ""
+    seeded = bool(_LOCK_SEED_RE.search(text))
+    created = bool(_PR_CREATED_RE.search(text))
+    if not (seeded and created):
+        return {"proven": True, "block": False, "reasons": []}
+
+    if _OVERRIDE_PROOF_RE.search(text):
+        return {"proven": True, "block": False, "reasons": []}
+
+    return {
+        "proven": False,
+        "block": True,
+        "reasons": [
+            "report created/opened a PR after manual issue-lock seeding without "
+            "operator override proof"
+        ],
+    }
+
+
+def assess_author_reviewer_same_run_report(report_text: str) -> dict:
+    """Reviewer handoff must not create and approve the same PR in one run (#447)."""
+    text = report_text or ""
+    if not (_PR_CREATED_RE.search(text) and _REVIEW_APPROVE_RE.search(text)):
+        return {"proven": True, "block": False, "reasons": []}
+    return {
+        "proven": False,
+        "block": True,
+        "reasons": [
+            "report mixes author-side PR creation and reviewer approval in one "
+            "final handoff; split author and reviewer sessions"
+        ],
+    }

issue_lock_store.py

@@ -0,0 +1,486 @@
+"""Atomic per-issue lock store (#438).
+
+Distinct issues use separate lock files under ``GITEA_ISSUE_LOCK_DIR`` so
+concurrent author sessions do not clobber each other. Acquisition is
+serialized per issue with ``fcntl.flock`` and fail-closed stale handling.
+"""
+
+from __future__ import annotations
+
+import errno
+import fcntl
+import json
+import os
+import tempfile
+import uuid
+from contextlib import contextmanager
+from datetime import datetime, timedelta, timezone
+from typing import Any
+
+DEFAULT_LOCK_DIR = os.environ.get("GITEA_ISSUE_LOCK_DIR", "/tmp/gitea_issue_locks")
+LEGACY_LOCK_FILE = os.environ.get("GITEA_ISSUE_LOCK_FILE", "/tmp/gitea_issue_lock.json")
+LOCK_VERSION = 1
+
+
+class LockContentionError(RuntimeError):
+    """Raised when an exclusive per-issue lock cannot be acquired."""
+
+
+def _sanitize(value: str) -> str:
+    text = (value or "").strip()
+    if not text:
+        return "unknown"
+    return "".join(c if c.isalnum() or c in "-_" else "-" for c in text)
+
+
+def lock_scope_key(remote: str, org: str, repo: str, issue_number: int) -> str:
+    return "_".join(
+        (
+            _sanitize(remote),
+            _sanitize(org),
+            _sanitize(repo),
+            f"issue-{issue_number}",
+        )
+    )
+
+
+def issue_lock_path(
+    remote: str,
+    org: str,
+    repo: str,
+    issue_number: int,
+    *,
+    lock_dir: str | None = None,
+) -> str:
+    base = (lock_dir or DEFAULT_LOCK_DIR).strip()
+    return os.path.join(base, f"{lock_scope_key(remote, org, repo, issue_number)}.json")
+
+
+def flock_path(json_path: str) -> str:
+    return f"{json_path}.lock"
+
+
+def _iso(value: datetime) -> str:
+    return value.astimezone(timezone.utc).replace(microsecond=0).isoformat().replace("+00:00", "Z")
+
+
+def parse_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 is_process_alive(pid: int | None) -> bool:
+    if not pid or pid <= 0:
+        return False
+    try:
+        os.kill(int(pid), 0)
+        return True
+    except OSError as exc:
+        return exc.errno != errno.ESRCH
+    except (TypeError, ValueError):
+        return False
+
+
+def read_lock_file(path: str) -> dict[str, Any] | None:
+    if not os.path.exists(path):
+        return None
+    try:
+        with open(path, encoding="utf-8") as handle:
+            data = json.load(handle)
+        return data if isinstance(data, dict) else None
+    except Exception:
+        return None
+
+
+def atomic_write_json(path: str, data: dict[str, Any]) -> None:
+    directory = os.path.dirname(path) or "."
+    os.makedirs(directory, exist_ok=True)
+    fd, tmp_path = tempfile.mkstemp(dir=directory, prefix=".lock-", suffix=".tmp")
+    try:
+        with os.fdopen(fd, "w", encoding="utf-8") as handle:
+            json.dump(data, handle)
+            handle.flush()
+            os.fsync(handle.fileno())
+        os.replace(tmp_path, path)
+    finally:
+        if os.path.exists(tmp_path):
+            os.remove(tmp_path)
+
+
+@contextmanager
+def _exclusive_file_lock(lock_path: str):
+    os.makedirs(os.path.dirname(lock_path) or ".", exist_ok=True)
+    fd = os.open(lock_path, os.O_CREAT | os.O_RDWR, 0o600)
+    try:
+        try:
+            fcntl.flock(fd, fcntl.LOCK_EX | fcntl.LOCK_NB)
+        except BlockingIOError as exc:
+            raise LockContentionError(
+                f"could not acquire exclusive lock on '{lock_path}'"
+            ) from exc
+        yield fd
+    finally:
+        try:
+            fcntl.flock(fd, fcntl.LOCK_UN)
+        finally:
+            os.close(fd)
+
+
+def _lease_expires_at(lock_data: dict[str, Any] | None) -> datetime | None:
+    if not lock_data:
+        return None
+    lease = lock_data.get("work_lease")
+    if isinstance(lease, dict):
+        return parse_timestamp(lease.get("expires_at"))
+    return parse_timestamp(lock_data.get("expires_at"))
+
+
+def assess_lock_freshness(
+    lock_data: dict[str, Any] | None,
+    *,
+    now: datetime | None = None,
+) -> dict[str, Any]:
+    """Classify a lock as live, expired, stale, or absent."""
+    current = now or datetime.now(timezone.utc)
+    if not lock_data:
+        return {
+            "status": "absent",
+            "live": False,
+            "stale": False,
+            "reason": "no lock record",
+        }
+
+    expires_at = _lease_expires_at(lock_data)
+    heartbeat_at = parse_timestamp(lock_data.get("last_heartbeat_at"))
+    if heartbeat_at is None and isinstance(lock_data.get("work_lease"), dict):
+        heartbeat_at = parse_timestamp(lock_data["work_lease"].get("last_heartbeat_at"))
+
+    pid = lock_data.get("pid")
+    pid_alive = is_process_alive(pid) if pid is not None else False
+
+    if expires_at and expires_at <= current:
+        return {
+            "status": "expired",
+            "live": False,
+            "stale": True,
+            "reason": f"lease expired at {expires_at.isoformat()}",
+            "pid_alive": pid_alive,
+        }
+
+    if pid is not None and not pid_alive:
+        return {
+            "status": "stale",
+            "live": False,
+            "stale": True,
+            "reason": f"owner pid {pid} is not alive",
+            "pid_alive": False,
+        }
+
+    return {
+        "status": "live",
+        "live": True,
+        "stale": False,
+        "reason": "lock heartbeat and lease are fresh",
+        "pid_alive": pid_alive,
+        "heartbeat_at": _iso(heartbeat_at) if heartbeat_at else None,
+        "expires_at": _iso(expires_at) if expires_at else None,
+    }
+
+
+def _same_owner(
+    existing: dict[str, Any],
+    *,
+    branch_name: str,
+    worktree_path: str,
+    claimant: dict[str, Any] | None,
+) -> bool:
+    same_branch = existing.get("branch_name") == branch_name
+    same_worktree = os.path.realpath(str(existing.get("worktree_path") or "")) == os.path.realpath(
+        worktree_path
+    )
+    if not (same_branch and same_worktree):
+        return False
+    if claimant and isinstance(existing.get("claimant"), dict):
+        return (
+            existing["claimant"].get("profile") == claimant.get("profile")
+            and existing["claimant"].get("username") == claimant.get("username")
+        )
+    return same_branch and same_worktree
+
+
+def update_legacy_session_pointer(record: dict[str, Any]) -> dict[str, Any]:
+    """Update the legacy global pointer without clobbering another live session."""
+    existing = read_lock_file(LEGACY_LOCK_FILE)
+    if existing:
+        freshness = assess_lock_freshness(existing)
+        if freshness["status"] == "live":
+            different_issue = existing.get("issue_number") != record.get("issue_number")
+            different_pid = existing.get("pid") != os.getpid()
+            if different_issue and different_pid and is_process_alive(existing.get("pid")):
+                return {
+                    "updated": False,
+                    "reason": (
+                        "retained global pointer for live issue "
+                        f"#{existing.get('issue_number')} pid={existing.get('pid')}; "
+                        f"per-issue lock at '{record.get('lock_path')}' is authoritative"
+                    ),
+                }
+    atomic_write_json(LEGACY_LOCK_FILE, record)
+    return {"updated": True, "path": LEGACY_LOCK_FILE}
+
+
+def acquire_issue_lock(
+    *,
+    issue_number: int,
+    branch_name: str,
+    remote: str,
+    org: str,
+    repo: str,
+    worktree_path: str,
+    work_lease: dict[str, Any],
+    claimant: dict[str, Any] | None = None,
+    lock_provenance: dict[str, Any] | None = None,
+    lock_dir: str | None = None,
+    allow_stale_recovery: bool = False,
+) -> dict[str, Any]:
+    """Acquire an atomic per-issue lock; fail closed on live competing ownership."""
+    path = issue_lock_path(remote, org, repo, issue_number, lock_dir=lock_dir)
+    sentinel = flock_path(path)
+    now = datetime.now(timezone.utc)
+    session_id = str(uuid.uuid4())
+    resolved_worktree = os.path.realpath(worktree_path)
+
+    try:
+        with _exclusive_file_lock(sentinel):
+            existing = read_lock_file(path)
+            freshness = assess_lock_freshness(existing, now=now)
+            if existing and freshness["live"]:
+                if not _same_owner(
+                    existing,
+                    branch_name=branch_name,
+                    worktree_path=resolved_worktree,
+                    claimant=claimant,
+                ):
+                    owner = existing.get("claimant") or {}
+                    raise RuntimeError(
+                        f"Issue #{issue_number} already has an active lock owned by "
+                        f"pid={existing.get('pid')} session={existing.get('session_id')} "
+                        f"profile={owner.get('profile')} on branch "
+                        f"'{existing.get('branch_name')}' (fail closed)"
+                    )
+            elif existing and freshness["stale"]:
+                if not allow_stale_recovery:
+                    raise RuntimeError(
+                        f"Issue #{issue_number} has a stale lock ({freshness['reason']}). "
+                        "Recovery review is required before takeover (fail closed)"
+                    )
+
+            record: dict[str, Any] = {
+                "lock_version": LOCK_VERSION,
+                "issue_number": issue_number,
+                "branch_name": branch_name,
+                "remote": remote,
+                "org": org,
+                "repo": repo,
+                "worktree_path": resolved_worktree,
+                "work_lease": work_lease,
+                "pid": os.getpid(),
+                "session_id": session_id,
+                "claimant": claimant or {},
+                "created_at": _iso(now),
+                "last_heartbeat_at": _iso(now),
+                "lock_path": path,
+            }
+            if lock_provenance:
+                record["lock_provenance"] = lock_provenance
+            atomic_write_json(path, record)
+            pointer = update_legacy_session_pointer(record)
+    except LockContentionError as exc:
+        competing = read_lock_file(path)
+        if competing:
+            freshness = assess_lock_freshness(competing, now=now)
+            owner = competing.get("claimant") or {}
+            raise RuntimeError(
+                f"Issue #{issue_number} lock contention: {exc}; competing owner "
+                f"pid={competing.get('pid')} session={competing.get('session_id')} "
+                f"profile={owner.get('profile')} status={freshness['status']} (fail closed)"
+            ) from exc
+        raise RuntimeError(f"Issue #{issue_number} lock contention: {exc} (fail closed)") from exc
+
+    freshness = assess_lock_freshness(record, now=now)
+    return {
+        "acquired": True,
+        "lock_path": path,
+        "session_id": session_id,
+        "freshness": freshness,
+        "legacy_pointer": pointer,
+        "lock_proof": format_lock_proof(record, freshness=freshness),
+        "record": record,
+    }
+
+
+def resolve_lock_for_issue(
+    *,
+    issue_number: int,
+    remote: str | None = None,
+    org: str | None = None,
+    repo: str | None = None,
+    lock_dir: str | None = None,
+) -> dict[str, Any] | None:
+    """Load the per-issue lock, falling back to the legacy global pointer."""
+    if remote and org and repo:
+        scoped = read_lock_file(
+            issue_lock_path(remote, org, repo, issue_number, lock_dir=lock_dir)
+        )
+        if scoped:
+            return scoped
+    legacy = read_lock_file(LEGACY_LOCK_FILE)
+    if legacy and legacy.get("issue_number") == issue_number:
+        return legacy
+    return None
+
+
+def resolve_lock_for_branch(
+    branch_name: str,
+    *,
+    lock_dir: str | None = None,
+) -> dict[str, Any] | None:
+    """Resolve a lock using the issue number embedded in a branch name."""
+    import re
+
+    match = re.search(r"issue-(\d+)", branch_name or "", re.IGNORECASE)
+    if not match:
+        legacy = read_lock_file(LEGACY_LOCK_FILE)
+        if legacy and legacy.get("branch_name") == branch_name:
+            return legacy
+        return None
+
+    issue_number = int(match.group(1))
+    base = (lock_dir or DEFAULT_LOCK_DIR).strip()
+    if os.path.isdir(base):
+        suffix = f"_issue-{issue_number}.json"
+        for name in os.listdir(base):
+            if name.endswith(suffix):
+                record = read_lock_file(os.path.join(base, name))
+                if record and record.get("branch_name") == branch_name:
+                    return record
+    legacy = read_lock_file(LEGACY_LOCK_FILE)
+    if legacy and legacy.get("issue_number") == issue_number:
+        return legacy
+    return None
+
+
+def verify_lock_for_mutation(
+    lock_data: dict[str, Any] | None,
+    *,
+    issue_number: int | None = None,
+    branch_name: str | None = None,
+    worktree_path: str | None = None,
+) -> dict[str, Any]:
+    """Re-check lock ownership immediately before a mutation (#438)."""
+    reasons: list[str] = []
+    if not lock_data:
+        return {"proven": False, "block": True, "reasons": ["issue lock is missing (fail closed)"]}
+
+    freshness = assess_lock_freshness(lock_data)
+    if not freshness["live"]:
+        reasons.append(f"issue lock is not live: {freshness['reason']} (fail closed)")
+
+    if issue_number is not None and lock_data.get("issue_number") != issue_number:
+        reasons.append(
+            f"issue lock targets #{lock_data.get('issue_number')}, expected #{issue_number} (fail closed)"
+        )
+
+    if branch_name is not None and lock_data.get("branch_name") != branch_name:
+        reasons.append(
+            f"issue lock branch '{lock_data.get('branch_name')}' does not match "
+            f"'{branch_name}' (fail closed)"
+        )
+
+    if worktree_path is not None:
+        locked = os.path.realpath(str(lock_data.get("worktree_path") or ""))
+        declared = os.path.realpath(worktree_path)
+        if locked != declared:
+            reasons.append(
+                f"issue lock worktree '{locked}' does not match declared '{declared}' (fail closed)"
+            )
+
+    return {
+        "proven": not reasons,
+        "block": bool(reasons),
+        "reasons": reasons,
+        "freshness": freshness,
+        "lock_proof": format_lock_proof(lock_data, freshness=freshness),
+    }
+
+
+def list_live_locks(*, lock_dir: str | None = None, now: datetime | None = None) -> list[dict[str, Any]]:
+    """Return live per-issue locks for queue visibility."""
+    base = (lock_dir or DEFAULT_LOCK_DIR).strip()
+    if not os.path.isdir(base):
+        return []
+
+    live: list[dict[str, Any]] = []
+    for name in sorted(os.listdir(base)):
+        if not name.endswith(".json"):
+            continue
+        record = read_lock_file(os.path.join(base, name))
+        if not record:
+            continue
+        freshness = assess_lock_freshness(record, now=now)
+        if freshness["live"]:
+            live.append(
+                {
+                    "issue_number": record.get("issue_number"),
+                    "branch_name": record.get("branch_name"),
+                    "remote": record.get("remote"),
+                    "org": record.get("org"),
+                    "repo": record.get("repo"),
+                    "worktree_path": record.get("worktree_path"),
+                    "pid": record.get("pid"),
+                    "session_id": record.get("session_id"),
+                    "claimant": record.get("claimant"),
+                    "freshness": freshness,
+                    "lock_path": record.get("lock_path") or os.path.join(base, name),
+                }
+            )
+    return live
+
+
+def format_lock_proof(
+    lock_data: dict[str, Any] | None,
+    *,
+    freshness: dict[str, Any] | None = None,
+    competing_live_locks: list[dict[str, Any]] | None = None,
+    released: bool | None = None,
+) -> str:
+    """Canonical issue-lock proof string for final reports."""
+    if not lock_data:
+        return "issue lock proof: not acquired"
+    fresh = freshness or assess_lock_freshness(lock_data)
+    owner = lock_data.get("claimant") or {}
+    parts = [
+        "issue lock proof:",
+        f"acquired issue #{lock_data.get('issue_number')}",
+        f"branch {lock_data.get('branch_name')}",
+        f"owner {owner.get('profile') or 'unknown'}",
+        f"pid {lock_data.get('pid')}",
+        f"session {lock_data.get('session_id')}",
+        f"freshness {fresh.get('status')}",
+    ]
+    if competing_live_locks is not None:
+        parts.append(
+            "no competing live lock"
+            if not competing_live_locks
+            else f"competing live locks {len(competing_live_locks)}"
+        )
+    if released is True:
+        parts.append("lock released")
+    elif released is False:
+        parts.append("lock retained")
+    return "; ".join(parts)

issue_work_duplicate_gate.py

@@ -0,0 +1,180 @@
+"""Early duplicate-work detection for author work-issue sessions (#400)."""
+
+from __future__ import annotations
+
+from typing import Any
+
+import issue_claim_heartbeat as claim_hb
+
+PHASE_LOCK = "lock_issue"
+PHASE_COMMIT = "commit"
+PHASE_PUSH = "push"
+PHASE_CREATE_PR = "create_pr"
+
+OUTCOME_DUPLICATE_PR_PREVENTED = "duplicate_pr_prevented"
+OUTCOME_DUPLICATE_BRANCH_PREVENTED = "duplicate_branch_prevented"
+OUTCOME_DUPLICATE_COMMIT_PREVENTED = "duplicate_commit_prevented"
+OUTCOME_DUPLICATE_WORK_NOT_PREVENTED = "duplicate_work_not_prevented"
+
+_ACTIVE_CLAIM_STATUSES = frozenset({"active", "awaiting_review"})
+
+
+def _issue_pattern(issue_number: int) -> str:
+    return f"issue-{int(issue_number)}"
+
+
+def _linked_open_pr(issue_number: int, open_prs: list[dict]) -> dict | None:
+    return claim_hb._linked_open_pr(issue_number, open_prs)
+
+
+def _matching_branches(
+    issue_number: int,
+    branch_names: list[str],
+    *,
+    locked_branch: str | None = None,
+) -> list[str]:
+    pattern = _issue_pattern(issue_number)
+    matches = [
+        name for name in (branch_names or [])
+        if pattern in (name or "").lower()
+    ]
+    if locked_branch:
+        locked = locked_branch.strip()
+        matches = [name for name in matches if name != locked]
+    return matches
+
+
+def assess_work_issue_duplicate_gate(
+    issue_number: int,
+    *,
+    open_prs: list[dict] | None = None,
+    branch_names: list[str] | None = None,
+    claim_entry: dict | None = None,
+    locked_branch: str | None = None,
+    phase: str = PHASE_LOCK,
+) -> dict[str, Any]:
+    """Fail closed when duplicate work is already in flight for an issue."""
+    reasons: list[str] = []
+    outcome = OUTCOME_DUPLICATE_WORK_NOT_PREVENTED
+    prs = list(open_prs or [])
+    branches = list(branch_names or [])
+    pattern = _issue_pattern(issue_number)
+
+    linked = _linked_open_pr(issue_number, prs)
+    if linked:
+        reasons.append(
+            f"open PR #{linked.get('number')} already covers issue "
+            f"#{issue_number} (fail closed)"
+        )
+        outcome = OUTCOME_DUPLICATE_PR_PREVENTED
+
+    conflicting_branches = _matching_branches(
+        issue_number, branches, locked_branch=locked_branch
+    )
+    if conflicting_branches:
+        names = ", ".join(conflicting_branches[:5])
+        reasons.append(
+            f"remote branch(es) already match issue pattern '{pattern}': "
+            f"{names} (fail closed)"
+        )
+        if outcome == OUTCOME_DUPLICATE_WORK_NOT_PREVENTED:
+            outcome = OUTCOME_DUPLICATE_BRANCH_PREVENTED
+
+    entry = claim_entry or {}
+    if entry.get("linked_open_pr") and not linked:
+        reasons.append(
+            f"claim inventory reports open PR #{entry['linked_open_pr']} "
+            f"for issue #{issue_number} (fail closed)"
+        )
+        outcome = OUTCOME_DUPLICATE_PR_PREVENTED
+
+    status = (entry.get("status") or "").strip().lower()
+    if status in _ACTIVE_CLAIM_STATUSES and not linked:
+        heartbeat = entry.get("latest_heartbeat") or {}
+        claim_branch = (heartbeat.get("branch") or "").strip()
+        if locked_branch and claim_branch and claim_branch != locked_branch:
+            reasons.append(
+                f"active claim lease on branch '{claim_branch}' blocks "
+                f"work on '{locked_branch}' for issue #{issue_number} "
+                "(fail closed)"
+            )
+            if outcome == OUTCOME_DUPLICATE_WORK_NOT_PREVENTED:
+                outcome = OUTCOME_DUPLICATE_BRANCH_PREVENTED
+        elif not locked_branch and status == "active":
+            reasons.append(
+                f"issue #{issue_number} has an active claim lease "
+                "(fail closed)"
+            )
+            if outcome == OUTCOME_DUPLICATE_WORK_NOT_PREVENTED:
+                outcome = OUTCOME_DUPLICATE_BRANCH_PREVENTED
+
+    if phase in {PHASE_COMMIT, PHASE_PUSH} and reasons:
+        if outcome == OUTCOME_DUPLICATE_PR_PREVENTED:
+            outcome = OUTCOME_DUPLICATE_COMMIT_PREVENTED
+        elif outcome == OUTCOME_DUPLICATE_BRANCH_PREVENTED:
+            outcome = OUTCOME_DUPLICATE_COMMIT_PREVENTED
+
+    block = bool(reasons)
+    return {
+        "block": block,
+        "performed": not block,
+        "issue_number": issue_number,
+        "phase": phase,
+        "outcome": outcome,
+        "linked_open_pr": linked.get("number") if linked else entry.get("linked_open_pr"),
+        "conflicting_branches": conflicting_branches,
+        "claim_status": status or None,
+        "reasons": reasons,
+        "safe_next_action": (
+            "stop before mutating; preserve local work and produce a "
+            "reconciliation handoff if a concurrent PR appeared after push"
+            if block and phase == PHASE_CREATE_PR
+            else "stop before mutating; do not commit or push duplicate work"
+            if block
+            else "proceed"
+        ),
+    }
+
+
+def assess_work_issue_duplicate_report(report_text: str) -> dict[str, Any]:
+    """Require explicit duplicate-work outcome wording in work-issue reports."""
+    text = (report_text or "").lower()
+    markers = {
+        OUTCOME_DUPLICATE_PR_PREVENTED: (
+            "duplicate pr prevented",
+            "duplicate_pr_prevented",
+        ),
+        OUTCOME_DUPLICATE_BRANCH_PREVENTED: (
+            "duplicate branch prevented",
+            "duplicate_branch_prevented",
+        ),
+        OUTCOME_DUPLICATE_COMMIT_PREVENTED: (
+            "duplicate commit prevented",
+            "duplicate_commit_prevented",
+        ),
+        OUTCOME_DUPLICATE_WORK_NOT_PREVENTED: (
+            "duplicate work not prevented",
+            "duplicate_work_not_prevented",
+            "no duplicate work",
+        ),
+    }
+    matched = [
+        key for key, phrases in markers.items()
+        if any(phrase in text for phrase in phrases)
+    ]
+    if len(matched) != 1:
+        return {
+            "complete": False,
+            "downgraded": True,
+            "reasons": [
+                "work-issue report must state exactly one duplicate-work "
+                "outcome (duplicate PR/branch/commit prevented, or "
+                "duplicate work not prevented)"
+            ],
+        }
+    return {
+        "complete": True,
+        "downgraded": False,
+        "outcome": matched[0],
+        "reasons": [],
+    }

merged_cleanup_reconcile.py

@@ -13,6 +13,7 @@ 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")
@@ -49,6 +50,10 @@ def read_issue_lock(path: str | None = None) -> dict[str, Any] | None:
 
 
 def has_active_issue_lock(branch: str, lock_path: str | None = None) -> bool:
+    lock = issue_lock_store.resolve_lock_for_branch(branch)
+    if lock and (lock.get("branch_name") or "").strip() == (branch or "").strip():
+        freshness = issue_lock_store.assess_lock_freshness(lock)
+        return freshness["live"]
     lock = read_issue_lock(lock_path)
     if not lock:
         return False

review_proofs.py

@@ -3624,9 +3624,12 @@ def assess_work_issue_mode_isolation(report_text: str) -> dict:
 
 def assess_work_issue_final_report(report_text: str) -> dict:
     """#139: composite verifier for work-issue final reports."""
+    from issue_work_duplicate_gate import assess_work_issue_duplicate_report
+
     checks = {
         "workflow_source": assess_work_issue_workflow_source(report_text),
         "mode_isolation": assess_work_issue_mode_isolation(report_text),
+        "duplicate_work_outcome": assess_work_issue_duplicate_report(report_text),
     }
 
     reasons = []

scripts/worktree-start

@@ -37,14 +37,27 @@ 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 [[ "$allow_unlinked" -eq 0 ]]; then
-  if [[ ! -f "/tmp/gitea_issue_lock.json" ]]; then
-    echo "Error: Issue lock file '/tmp/gitea_issue_lock.json' is missing. You must lock exactly one issue before branch creation (fail closed)." >&2
+  locked_branch=$(PYTHONPATH="$repo_root" python3 - <<'PY' "$branch")
+import sys
+import issue_lock_store
+
+branch = sys.argv[1]
+lock = issue_lock_store.resolve_lock_for_branch(branch)
+if not lock:
+    print("", end="")
+    sys.exit(1)
+print(lock.get("branch_name", ""), end="")
+PY
+  )
+  if [[ -z "$locked_branch" ]]; then
+    echo "Error: No issue lock found for branch '$branch'. Lock the 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 +81,6 @@ 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/work-issue.md

@@ -297,6 +297,36 @@ Report:
 
 Do not create another branch/PR for the same issue unless the project explicitly allows taking over or updating existing work and exact capability is proven.
 
+### 10A. Duplicate-work gate phases (#400)
+
+Before any file edits, prove duplicate-work clearance with
+`gitea_assess_work_issue_duplicate` or `gitea_lock_issue` (which runs the same
+gate). The gate checks live:
+
+* open PRs linked to the issue (head branch or Closes/Fixes reference),
+* remote branches matching `issue-<number>`,
+* active claim leases from structured heartbeats.
+
+Re-check immediately before:
+
+* `gitea_commit_files` (commit),
+* branch push,
+* `gitea_create_pr` (PR creation).
+
+If a concurrent open PR appears after work begins:
+
+* before commit/push → stop and preserve local work without pushing,
+* after commit but before push → stop without pushing,
+* after push but before PR creation → stop and produce a reconciliation
+  handoff instead of opening a PR.
+
+Final reports must state exactly one duplicate-work outcome:
+
+* `duplicate PR prevented`
+* `duplicate branch prevented`
+* `duplicate commit prevented`
+* `duplicate work not prevented`
+
 ## 11. Claim or lock the issue before implementation
 
 Claim/lock the issue before implementation if the project provides a claim/lock mechanism.
@@ -717,6 +747,12 @@ Use only precise categories:
 * External-state mutations:
 * Read-only diagnostics:
 
+Issue-lock file (`/tmp/gitea_issue_lock.json`) read/write/delete is always an
+external-state mutation. Never claim `External-state mutations: none` after
+seeding, restoring, or removing that file. Manual lock seeding is not a normal
+recovery path (#447); use `gitea_lock_issue` or the #442 adoption recovery path
+instead. Link broader redesign: #438.
+
 `git fetch`, `git remote update`, and any command that updates refs must be listed under `Git ref mutations`, not read-only diagnostics.
 
 If `git reset --hard`, checkout, clean, worktree add/remove, merge simulation, merge abort, or similar commands occurred, report them under `Worktree/index mutations`.

tests/test_agent_temp_artifacts.py

@@ -80,7 +80,10 @@ class TestIssueLockArtifactWarning(unittest.TestCase):
     def tearDown(self):
         self._env_patcher.stop()
 
-    @patch("mcp_server.api_get_all", return_value=[])
+    @patch(
+        "mcp_server.issue_duplicate_context_fetcher",
+        return_value=([], [], {"status": "not_claimed"}),
+    )
     @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())

tests/test_commit_files_capability.py

@@ -76,7 +76,14 @@ class CommitFilesCapabilityBase(unittest.TestCase):
         with open(self.config_path, "w", encoding="utf-8") as fh:
             fh.write(json.dumps(CONFIG))
 
+        self._dup_fetcher_patcher = patch(
+            "mcp_server.issue_duplicate_context_fetcher",
+            return_value=([], [], {"status": "not_claimed"}),
+        )
+        self._dup_fetcher_patcher.start()
+
     def tearDown(self):
+        self._dup_fetcher_patcher.stop()
         self._remotes.stop()
         mcp_server._IDENTITY_CACHE.clear()
         mcp_server._preflight_whoami_called, mcp_server._preflight_capability_called = (

tests/test_commit_payloads.py

@@ -67,6 +67,15 @@ 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_provenance
+
+        work_lease = {
+            "operation_type": "author_issue_work",
+            "issue_number": 263,
+            "branch": "feat/issue-263-native-commit-payloads",
+            "claimant": {"username": "test-user", "profile": "test-author"},
+            "expires_at": "2999-01-01T00:00:00Z",
+        }
         self.lock_data = {
             "issue_number": 263,
             "branch_name": "feat/issue-263-native-commit-payloads",
@@ -74,6 +83,11 @@ class TestCommitPayloads(unittest.TestCase):
             "org": "Example-Org",
             "repo": "Example-Repo",
             "worktree_path": self.locked_worktree_path,
+            "work_lease": work_lease,
+            "lock_provenance": issue_lock_provenance.build_sanctioned_lock_provenance(
+                tool="gitea_lock_issue",
+                claimant=work_lease.get("claimant"),
+            ),
         }
         with open(self.lock_file_path, "w", encoding="utf-8") as fh:
             fh.write(json.dumps(self.lock_data))
@@ -84,7 +98,14 @@ class TestCommitPayloads(unittest.TestCase):
         mcp_server._preflight_whoami_called = True
         mcp_server._preflight_capability_called = True
 
+        self._dup_fetcher_patcher = patch(
+            "mcp_server.issue_duplicate_context_fetcher",
+            return_value=([], [], {"status": "not_claimed"}),
+        )
+        self._dup_fetcher_patcher.start()
+
     def tearDown(self):
+        self._dup_fetcher_patcher.stop()
         self._remotes.stop()
         mcp_server._IDENTITY_CACHE.clear()
 

tests/test_issue_lock_provenance.py

@@ -0,0 +1,130 @@
+"""Tests for issue-lock provenance and external-state disclosure (#447)."""
+
+from __future__ import annotations
+
+import sys
+import unittest
+from pathlib import Path
+
+sys.path.insert(0, str(Path(__file__).resolve().parent.parent))
+
+import issue_lock_provenance as ilp  # noqa: E402
+from final_report_validator import assess_final_report_validator  # noqa: E402
+
+
+def _sanctioned_lock(**overrides):
+    work_lease = {
+        "operation_type": "author_issue_work",
+        "issue_number": 447,
+        "branch": "feat/issue-447-lock-provenance",
+        "claimant": {"username": "jcwalker3", "profile": "prgs-author"},
+        "expires_at": "2999-01-01T00:00:00Z",
+    }
+    data = {
+        "issue_number": 447,
+        "branch_name": "feat/issue-447-lock-provenance",
+        "work_lease": work_lease,
+        "lock_provenance": ilp.build_sanctioned_lock_provenance(
+            tool="gitea_lock_issue",
+            claimant=work_lease["claimant"],
+        ),
+    }
+    data.update(overrides)
+    return data
+
+
+class TestLockProvenanceForCreatePr(unittest.TestCase):
+    def test_sanctioned_lock_passes(self):
+        result = ilp.assess_lock_file_for_create_pr(_sanctioned_lock())
+        self.assertTrue(result["proven"])
+        self.assertFalse(result["block"])
+
+    def test_manual_seed_without_provenance_blocked(self):
+        result = ilp.assess_lock_file_for_create_pr(
+            {"issue_number": 420, "branch_name": "feat/x", "work_lease": {}}
+        )
+        self.assertTrue(result["block"])
+        self.assertIn("lock_provenance", result["reasons"][0])
+
+    def test_operator_override_requires_reason(self):
+        result = ilp.assess_lock_file_for_create_pr(
+            _sanctioned_lock(
+                lock_provenance=ilp.build_sanctioned_lock_provenance(
+                    tool="operator_override",
+                    source=ilp.SOURCE_OPERATOR_OVERRIDE,
+                )
+            )
+        )
+        self.assertTrue(result["block"])
+
+
+class TestExternalStateReportRules(unittest.TestCase):
+    def test_seed_with_external_none_blocked(self):
+        report = (
+            "Restored /tmp/gitea_issue_lock.json to unblock PR creation.\n"
+            "- External-state mutations: none\n"
+        )
+        result = ilp.assess_issue_lock_external_state_report(report)
+        self.assertTrue(result["block"])
+
+    def test_seed_with_disclosure_passes(self):
+        report = (
+            "Restored /tmp/gitea_issue_lock.json after MCP restart.\n"
+            "- External-state mutations: wrote /tmp/gitea_issue_lock.json\n"
+        )
+        result = ilp.assess_issue_lock_external_state_report(report)
+        self.assertTrue(result["proven"])
+
+    def test_remove_claimed_as_cleanup_only_blocked(self):
+        report = (
+            "rm /tmp/gitea_issue_lock.json after PR creation.\n"
+            "- Cleanup mutations: lock removed\n"
+            "- External-state mutations: none\n"
+        )
+        result = ilp.assess_issue_lock_external_state_report(report)
+        self.assertTrue(result["block"])
+
+    def test_manual_lock_pr_without_override_blocked(self):
+        report = (
+            "Programmatically seeded gitea_issue_lock.json then gitea_create_pr.\n"
+            "PR #444 created.\n"
+        )
+        result = ilp.assess_manual_lock_pr_without_override(report)
+        self.assertTrue(result["block"])
+
+    def test_author_reviewer_same_run_blocked(self):
+        report = (
+            "gitea_create_pr opened PR #444.\n"
+            "Submitted approve review on PR #444.\n"
+        )
+        result = ilp.assess_author_reviewer_same_run_report(report)
+        self.assertTrue(result["block"])
+
+
+class TestFinalReportValidatorIntegration(unittest.TestCase):
+    def test_work_issue_blocks_hidden_lock_mutation(self):
+        report = (
+            "## Controller Handoff\n"
+            "- Task: work issue #420\n"
+            "- External-state mutations: none\n"
+            "Restored /tmp/gitea_issue_lock.json before PR creation.\n"
+        )
+        result = assess_final_report_validator(report, "work_issue")
+        rule_ids = {f["rule_id"] for f in result["findings"]}
+        self.assertIn("shared.issue_lock_external_state", rule_ids)
+        self.assertTrue(result["blocked"])
+
+    def test_review_pr_blocks_create_and_approve(self):
+        report = (
+            "## Controller Handoff\n"
+            "- Task: review PR #444\n"
+            "- Review decision: approve\n"
+            "Created PR #444 via gitea_create_pr earlier in this run.\n"
+        )
+        result = assess_final_report_validator(report, "review_pr")
+        rule_ids = {f["rule_id"] for f in result["findings"]}
+        self.assertIn("shared.author_reviewer_same_run", rule_ids)
+
+
+if __name__ == "__main__":
+    unittest.main()

tests/test_issue_lock_store.py

@@ -0,0 +1,206 @@
+"""Tests for atomic per-issue lock store (#438)."""
+
+from __future__ import annotations
+
+import os
+import sys
+import tempfile
+import threading
+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 issue_lock_store  # noqa: E402
+
+
+def _lease(**overrides):
+    now = datetime.now(timezone.utc)
+    lease = {
+        "operation_type": "author_issue_work",
+        "issue_number": 438,
+        "branch": "feat/issue-438-lock-hardening",
+        "worktree_path": "/tmp/wt",
+        "expires_at": (now + timedelta(hours=4)).isoformat().replace("+00:00", "Z"),
+        "last_heartbeat_at": now.isoformat().replace("+00:00", "Z"),
+    }
+    lease.update(overrides)
+    return lease
+
+
+class TestIssueLockStore(unittest.TestCase):
+    def setUp(self):
+        self.tempdir = tempfile.mkdtemp(prefix="issue-lock-store-")
+        self.legacy = os.path.join(self.tempdir, "legacy.json")
+        self.addCleanup(self._cleanup)
+
+    def _cleanup(self):
+        for root, _dirs, files in os.walk(self.tempdir, topdown=False):
+            for name in files:
+                try:
+                    os.remove(os.path.join(root, name))
+                except OSError:
+                    pass
+            try:
+                os.rmdir(root)
+            except OSError:
+                pass
+
+    def _acquire(self, issue_number=438, branch="feat/issue-438-lock-hardening", **kwargs):
+        worktree_path = kwargs.pop("worktree_path", "/tmp/wt")
+        return issue_lock_store.acquire_issue_lock(
+            issue_number=issue_number,
+            branch_name=branch,
+            remote="prgs",
+            org="Scaled-Tech-Consulting",
+            repo="Gitea-Tools",
+            worktree_path=worktree_path,
+            work_lease=_lease(issue_number=issue_number, branch=branch),
+            claimant={"profile": "prgs-author", "username": "jcwalker3"},
+            lock_dir=self.tempdir,
+            **kwargs,
+        )
+
+    def test_acquire_writes_per_issue_lock_and_legacy_pointer(self):
+        with patch.object(issue_lock_store, "LEGACY_LOCK_FILE", self.legacy):
+            result = self._acquire()
+        path = issue_lock_store.issue_lock_path("prgs", "Scaled-Tech-Consulting", "Gitea-Tools", 438, lock_dir=self.tempdir)
+        self.assertTrue(os.path.exists(path))
+        self.assertTrue(result["acquired"])
+        self.assertIn("lock_proof", result)
+        with open(self.legacy, encoding="utf-8") as handle:
+            legacy = __import__("json").load(handle)
+        self.assertEqual(legacy["issue_number"], 438)
+        self.assertEqual(legacy["session_id"], result["session_id"])
+
+    def test_concurrent_acquire_same_issue_only_one_wins(self):
+        barrier = threading.Barrier(2)
+        results: list[dict | Exception] = []
+
+        def worker():
+            barrier.wait()
+            try:
+                results.append(self._acquire())
+            except Exception as exc:  # noqa: BLE001
+                results.append(exc)
+
+        threads = [threading.Thread(target=worker) for _ in range(2)]
+        for thread in threads:
+            thread.start()
+        for thread in threads:
+            thread.join()
+
+        successes = [item for item in results if isinstance(item, dict)]
+        failures = [item for item in results if isinstance(item, Exception)]
+        self.assertEqual(len(successes), 1)
+        self.assertEqual(len(failures), 1)
+        failure_text = str(failures[0]).lower()
+        self.assertTrue(
+            "active lock" in failure_text or "lock contention" in failure_text,
+            failures[0],
+        )
+
+    def test_distinct_issues_acquire_without_contention(self):
+        first = self._acquire(issue_number=438, branch="feat/issue-438-lock-hardening")
+        second = self._acquire(
+            issue_number=440,
+            branch="feat/issue-440-recovery",
+            worktree_path="/tmp/other-wt",
+        )
+        self.assertTrue(first["acquired"])
+        self.assertTrue(second["acquired"])
+        self.assertNotEqual(first["session_id"], second["session_id"])
+
+    def test_stale_lock_requires_explicit_recovery(self):
+        path = issue_lock_store.issue_lock_path("prgs", "Scaled-Tech-Consulting", "Gitea-Tools", 438, lock_dir=self.tempdir)
+        stale = {
+            "lock_version": 1,
+            "issue_number": 438,
+            "branch_name": "feat/issue-438-old",
+            "remote": "prgs",
+            "org": "Scaled-Tech-Consulting",
+            "repo": "Gitea-Tools",
+            "worktree_path": "/tmp/old",
+            "pid": 999999,
+            "session_id": "stale-session",
+            "work_lease": _lease(expires_at="2000-01-01T00:00:00Z"),
+            "last_heartbeat_at": "2000-01-01T00:00:00Z",
+            "lock_path": path,
+        }
+        issue_lock_store.atomic_write_json(path, stale)
+        with self.assertRaises(RuntimeError) as ctx:
+            self._acquire()
+        self.assertIn("Recovery review is required", str(ctx.exception))
+
+        recovered = self._acquire(allow_stale_recovery=True)
+        self.assertTrue(recovered["acquired"])
+
+    def test_verify_lock_for_mutation_blocks_stale_lock(self):
+        record = {
+            "issue_number": 438,
+            "branch_name": "feat/issue-438-lock-hardening",
+            "worktree_path": "/tmp/wt",
+            "pid": 999999,
+            "work_lease": _lease(expires_at="2000-01-01T00:00:00Z"),
+            "last_heartbeat_at": "2000-01-01T00:00:00Z",
+        }
+        result = issue_lock_store.verify_lock_for_mutation(
+            record,
+            issue_number=438,
+            branch_name="feat/issue-438-lock-hardening",
+            worktree_path="/tmp/wt",
+        )
+        self.assertTrue(result["block"])
+        self.assertIn("not live", result["reasons"][0])
+
+    def test_list_live_locks_excludes_stale_records(self):
+        path = issue_lock_store.issue_lock_path("prgs", "Scaled-Tech-Consulting", "Gitea-Tools", 438, lock_dir=self.tempdir)
+        issue_lock_store.atomic_write_json(
+            path,
+            {
+                "issue_number": 438,
+                "branch_name": "feat/issue-438-lock-hardening",
+                "remote": "prgs",
+                "org": "Scaled-Tech-Consulting",
+                "repo": "Gitea-Tools",
+                "worktree_path": "/tmp/wt",
+                "pid": os.getpid(),
+                "session_id": "live",
+                "work_lease": _lease(),
+                "last_heartbeat_at": datetime.now(timezone.utc).isoformat().replace("+00:00", "Z"),
+                "lock_path": path,
+            },
+        )
+        stale_path = issue_lock_store.issue_lock_path("prgs", "Scaled-Tech-Consulting", "Gitea-Tools", 440, lock_dir=self.tempdir)
+        issue_lock_store.atomic_write_json(
+            stale_path,
+            {
+                "issue_number": 440,
+                "branch_name": "feat/issue-440-recovery",
+                "remote": "prgs",
+                "org": "Scaled-Tech-Consulting",
+                "repo": "Gitea-Tools",
+                "worktree_path": "/tmp/wt",
+                "pid": 999999,
+                "session_id": "stale",
+                "work_lease": _lease(issue_number=440, branch="feat/issue-440-recovery", expires_at="2000-01-01T00:00:00Z"),
+                "last_heartbeat_at": "2000-01-01T00:00:00Z",
+                "lock_path": stale_path,
+            },
+        )
+        live = issue_lock_store.list_live_locks(lock_dir=self.tempdir)
+        self.assertEqual([entry["issue_number"] for entry in live], [438])
+
+    def test_resolve_lock_for_branch_reads_per_issue_file(self):
+        self._acquire()
+        resolved = issue_lock_store.resolve_lock_for_branch(
+            "feat/issue-438-lock-hardening",
+            lock_dir=self.tempdir,
+        )
+        self.assertIsNotNone(resolved)
+        self.assertEqual(resolved["issue_number"], 438)
+
+
+if __name__ == "__main__":
+    unittest.main()

tests/test_issue_work_duplicate_gate.py

@@ -0,0 +1,251 @@
+"""Tests for early duplicate-work detection (#400)."""
+import json
+import os
+import sys
+import tempfile
+import unittest
+from pathlib import Path
+from unittest.mock import patch
+
+sys.path.insert(0, str(Path(__file__).resolve().parent.parent))
+
+import issue_work_duplicate_gate as dup_gate
+import mcp_server
+from issue_work_duplicate_gate import (
+    OUTCOME_DUPLICATE_BRANCH_PREVENTED,
+    OUTCOME_DUPLICATE_COMMIT_PREVENTED,
+    OUTCOME_DUPLICATE_PR_PREVENTED,
+    OUTCOME_DUPLICATE_WORK_NOT_PREVENTED,
+    PHASE_COMMIT,
+    PHASE_CREATE_PR,
+    PHASE_LOCK,
+    assess_work_issue_duplicate_gate,
+    assess_work_issue_duplicate_report,
+)
+
+
+class TestDuplicateGateAssessment(unittest.TestCase):
+    def test_clear_issue_passes(self):
+        result = assess_work_issue_duplicate_gate(
+            400,
+            open_prs=[],
+            branch_names=["feat/other-issue-99"],
+            claim_entry={"status": "not_claimed"},
+            locked_branch="feat/issue-400-duplicate-work-preflight",
+            phase=PHASE_LOCK,
+        )
+        self.assertFalse(result["block"])
+        self.assertEqual(result["outcome"], OUTCOME_DUPLICATE_WORK_NOT_PREVENTED)
+
+    def test_open_pr_blocks(self):
+        prs = [{
+            "number": 397,
+            "title": "feat: handoff",
+            "body": "Closes #395",
+            "head": {"ref": "feat/issue-395-proof-backed-review-handoff"},
+        }]
+        result = assess_work_issue_duplicate_gate(
+            395,
+            open_prs=prs,
+            branch_names=[],
+            phase=PHASE_LOCK,
+        )
+        self.assertTrue(result["block"])
+        self.assertEqual(result["outcome"], OUTCOME_DUPLICATE_PR_PREVENTED)
+
+    def test_conflicting_remote_branch_blocks(self):
+        result = assess_work_issue_duplicate_gate(
+            395,
+            open_prs=[],
+            branch_names=["feat/issue-395-proof-backed-handoff-claims"],
+            locked_branch="feat/issue-395-new-attempt",
+            phase=PHASE_LOCK,
+        )
+        self.assertTrue(result["block"])
+        self.assertEqual(result["outcome"], OUTCOME_DUPLICATE_BRANCH_PREVENTED)
+
+    def test_active_claim_on_other_branch_blocks(self):
+        result = assess_work_issue_duplicate_gate(
+            398,
+            open_prs=[],
+            branch_names=[],
+            claim_entry={
+                "status": "active",
+                "latest_heartbeat": {
+                    "branch": "feat/issue-398-validation-cwd-proof",
+                },
+            },
+            locked_branch="feat/issue-398-other-branch",
+            phase=PHASE_LOCK,
+        )
+        self.assertTrue(result["block"])
+
+    def test_commit_phase_maps_to_commit_outcome(self):
+        prs = [{
+            "number": 411,
+            "title": "x",
+            "body": "Closes #398",
+            "head": {"ref": "feat/issue-398-validation-cwd-proof"},
+        }]
+        result = assess_work_issue_duplicate_gate(
+            398,
+            open_prs=prs,
+            branch_names=[],
+            locked_branch="feat/issue-398-alt",
+            phase=PHASE_COMMIT,
+        )
+        self.assertTrue(result["block"])
+        self.assertEqual(result["outcome"], OUTCOME_DUPLICATE_COMMIT_PREVENTED)
+
+    def test_stale_claim_does_not_block_by_status_alone(self):
+        result = assess_work_issue_duplicate_gate(
+            400,
+            open_prs=[],
+            branch_names=[],
+            claim_entry={"status": "reclaimable", "reasons": ["stale"]},
+            locked_branch="feat/issue-400-duplicate-work-preflight",
+            phase=PHASE_LOCK,
+        )
+        self.assertFalse(result["block"])
+
+
+class TestDuplicateReportOutcome(unittest.TestCase):
+    def test_requires_exactly_one_outcome(self):
+        bad = assess_work_issue_duplicate_report("work finished")
+        self.assertFalse(bad["complete"])
+
+        good = assess_work_issue_duplicate_report(
+            "Duplicate work not prevented for issue #400."
+        )
+        self.assertTrue(good["complete"])
+        self.assertEqual(good["outcome"], OUTCOME_DUPLICATE_WORK_NOT_PREVENTED)
+
+
+class TestInjectableDuplicateFetcher(unittest.TestCase):
+    @patch("mcp_server.get_auth_header", return_value="token x")
+    def test_lock_issue_uses_injected_fetcher(self, _auth):
+        seen = {}
+
+        def fetcher(h, o, r, auth, issue_number):
+            seen["issue_number"] = issue_number
+            return [], [], {"status": "not_claimed"}
+
+        with patch(
+            "mcp_server.issue_duplicate_context_fetcher",
+            side_effect=fetcher,
+        ), patch(
+            "mcp_server.issue_lock_worktree.read_worktree_git_state",
+            return_value={
+                "current_branch": "master",
+                "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",
+                )
+        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._lock_patch.start()
+        self._remotes = patch.dict(mcp_server.REMOTES, {
+            "prgs": {"host": "gitea.example.com", "org": "Example-Org",
+                     "repo": "Example-Repo"},
+        })
+        self._remotes.start()
+        mcp_server._IDENTITY_CACHE.clear()
+
+    def tearDown(self):
+        patch.stopall()
+        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)
+
+    @patch("mcp_server._assess_issue_duplicate_gate")
+    @patch("mcp_server.get_profile", return_value={
+        "profile_name": "test-author",
+        "allowed_operations": ["gitea.read", "gitea.repo.commit"],
+        "forbidden_operations": [],
+        "audit_label": "test-author",
+    })
+    @patch("mcp_server.get_auth_header", return_value="token x")
+    def test_commit_files_blocked_on_recheck(self, _auth, _profile, mock_gate):
+        self._write_lock()
+        mock_gate.return_value = {
+            "block": True,
+            "reasons": ["open PR #412 already covers issue #400"],
+            "outcome": OUTCOME_DUPLICATE_COMMIT_PREVENTED,
+            "safe_next_action": "stop",
+        }
+        mcp_server.record_preflight_check("whoami")
+        mcp_server.record_preflight_check("capability", resolved_role="author")
+        with patch(
+            "mcp_server.role_session_router.check_author_mutation_after_reviewer_stop",
+            return_value=(True, []),
+        ):
+            result = mcp_server.gitea_commit_files(
+                files=[{
+                    "operation": "create",
+                    "path": "a.txt",
+                    "content_plain": "hi",
+                }],
+                message="test",
+                remote="prgs",
+            )
+        self.assertFalse(result["success"])
+        self.assertIn("duplicate_gate", result)
+
+    @patch("mcp_server._assess_issue_duplicate_gate")
+    @patch("mcp_server.get_profile", return_value={
+        "profile_name": "test-author",
+        "allowed_operations": ["gitea.read", "gitea.pr.create"],
+        "forbidden_operations": [],
+        "audit_label": "test-author",
+    })
+    @patch("mcp_server.get_auth_header", return_value="token x")
+    def test_create_pr_returns_handoff_on_duplicate(self, _auth, _profile, mock_gate):
+        self._write_lock()
+        mock_gate.return_value = {
+            "block": True,
+            "reasons": ["open PR #412 already covers issue #400"],
+            "outcome": OUTCOME_DUPLICATE_PR_PREVENTED,
+            "safe_next_action": "reconciliation handoff",
+        }
+        mcp_server.record_preflight_check("whoami")
+        mcp_server.record_preflight_check("capability", resolved_role="author")
+        with patch(
+            "mcp_server.role_session_router.check_author_mutation_after_reviewer_stop",
+            return_value=(True, []),
+        ):
+            result = mcp_server.gitea_create_pr(
+                title="feat: x (Closes #400)",
+                head="feat/issue-400-x",
+                base="master",
+                body="Closes #400",
+                remote="prgs",
+            )
+        self.assertFalse(result["success"])
+        self.assertIsNone(result.get("number"))
+        self.assertIn("duplicate_gate", result)
+
+
+if __name__ == "__main__":
+    unittest.main()

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"
 
@@ -101,17 +103,60 @@ ISSUE_LOCK_FILE = "/tmp/gitea_issue_lock.json"
 
 
 def _sample_issue_lock(issue_number=123, branch_name="feat/x", **overrides):
+    import issue_lock_provenance
+
+    work_lease = {
+        "operation_type": "author_issue_work",
+        "issue_number": issue_number,
+        "branch": branch_name,
+        "claimant": {"username": "test-user", "profile": "test-author"},
+        "expires_at": "2999-01-01T00:00:00Z",
+    }
     record = {
         "issue_number": issue_number,
         "branch_name": branch_name,
         "remote": "dadeschools",
         "org": "Scaled-Tech-Consulting",
         "repo": "Gitea-Tools",
+        "work_lease": work_lease,
+        "lock_provenance": issue_lock_provenance.build_sanctioned_lock_provenance(
+            tool="gitea_lock_issue",
+            claimant=work_lease.get("claimant"),
+        ),
     }
     record.update(overrides)
     return record
 
 
+def _clear_duplicate_context_fetcher(*_args, **_kwargs):
+    """Default injectable duplicate-work context for lock/create_pr tests."""
+    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
+    worktree = record.get("worktree_path") or os.path.realpath(os.getcwd())
+    acquisition = issue_lock_store.acquire_issue_lock(
+        issue_number=int(record["issue_number"]),
+        branch_name=str(record["branch_name"]),
+        remote=remote,
+        org=str(record["org"]),
+        repo=str(record["repo"]),
+        worktree_path=worktree,
+        work_lease=record["work_lease"],
+        claimant=record["work_lease"].get("claimant"),
+        lock_provenance=record.get("lock_provenance"),
+        lock_dir=os.environ.get("GITEA_ISSUE_LOCK_DIR"),
+    )
+    return acquisition["lock_path"]
+
+
 # ---------------------------------------------------------------------------
 # Create Issue
 # ---------------------------------------------------------------------------
@@ -166,55 +211,78 @@ class TestCreateIssue(unittest.TestCase):
 # ---------------------------------------------------------------------------
 class TestCreatePR(unittest.TestCase):
 
+    @patch(
+        "mcp_server.issue_duplicate_context_fetcher",
+        return_value=([], [], {"status": "not_claimed"}),
+    )
     @patch("mcp_server.role_session_router.check_author_mutation_after_reviewer_stop",
            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):
-        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")
         self.assertIn("Closes #123", payload["title"])
 
+    @patch(
+        "mcp_server.issue_duplicate_context_fetcher",
+        return_value=([], [], {"status": "not_claimed"}),
+    )
     @patch("mcp_server.role_session_router.check_author_mutation_after_reviewer_stop",
            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):
-        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 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):
-            result = gitea_create_pr(title="feat: X Closes #123", head="feat/x", base="main")
+                _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):
+    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")
+                    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")
 
 
 # ---------------------------------------------------------------------------
@@ -3042,22 +3110,51 @@ 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)
+        import shutil
+        import tempfile
+
+        self._lock_dir = tempfile.mkdtemp(prefix="mcp-issue-lock-")
+        self._session_lock = os.path.join(self._lock_dir, "session.json")
+        env = {
+            **ISSUE_WRITE_ENV,
+            "GITEA_ISSUE_LOCK_DIR": self._lock_dir,
+            "GITEA_ISSUE_LOCK_FILE": self._session_lock,
+        }
+        self._env_patcher = patch.dict(os.environ, env, clear=True)
         self._env_patcher.start()
+        self._patchers = [
+            patch("mcp_server.ISSUE_LOCK_FILE", self._session_lock),
+            patch("mcp_server.issue_lock_store.DEFAULT_LOCK_DIR", self._lock_dir),
+            patch("mcp_server.issue_lock_store.LEGACY_LOCK_FILE", self._session_lock),
+            patch("tests.test_mcp_server.ISSUE_LOCK_FILE", self._session_lock),
+            patch(
+                "mcp_server.issue_lock_worktree.read_worktree_git_state",
+                return_value=_clean_master_git_state_for_lock(),
+            ),
+        ]
+        for patcher in self._patchers:
+            patcher.start()
+        self._dup_fetcher_patcher = patch(
+            "mcp_server.issue_duplicate_context_fetcher",
+            return_value=([], [], {"status": "not_claimed"}),
+        )
+        self.mock_dup_fetcher = self._dup_fetcher_patcher.start()
 
     def tearDown(self):
+        import shutil
+
+        self._dup_fetcher_patcher.stop()
+        for patcher in reversed(getattr(self, "_patchers", [])):
+            patcher.stop()
         self._env_patcher.stop()
-        if os.path.exists(ISSUE_LOCK_FILE):
-            os.remove(ISSUE_LOCK_FILE)
+        shutil.rmtree(getattr(self, "_lock_dir", ""), ignore_errors=True)
 
     @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_success(self, _auth, mock_api, _git_state):
-        mock_api.return_value = [] # no open PRs
+    def test_lock_issue_success(self, _auth, _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")
@@ -3082,50 +3179,48 @@ class TestIssueLocking(unittest.TestCase):
         "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_reused_by_open_pr_branch(self, _auth, mock_api, _git_state):
-        mock_api.return_value = [{
+    def test_lock_issue_reused_by_open_pr_branch(self, _auth, _git_state):
+        self.mock_dup_fetcher.return_value = ([{
             "number": 200,
             "head": {"ref": "feat/issue-196-boundary"},
             "title": "Some PR",
-            "body": "No closes ref"
-        }]
+            "body": "No closes ref",
+        }], [], {"status": "not_claimed"})
         with self.assertRaises(ValueError) as ctx:
             gitea_lock_issue(issue_number=196, branch_name="feat/issue-196-mutations", remote="prgs")
-        self.assertIn("already tied to an open PR", str(ctx.exception))
+        self.assertIn("open PR #200 already covers issue", str(ctx.exception))
 
     @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_reused_by_open_pr_closes_ref(self, _auth, mock_api, _git_state):
-        mock_api.return_value = [{
+    def test_lock_issue_reused_by_open_pr_closes_ref(self, _auth, _git_state):
+        self.mock_dup_fetcher.return_value = ([{
             "number": 200,
             "head": {"ref": "feat/other-branch"},
             "title": "Some PR",
-            "body": "fixes #196"
-        }]
+            "body": "fixes #196",
+        }], [], {"status": "not_claimed"})
         with self.assertRaises(ValueError) as ctx:
             gitea_lock_issue(issue_number=196, branch_name="feat/issue-196-mutations", remote="prgs")
-        self.assertIn("already tied to an open PR", str(ctx.exception))
+        self.assertIn("open PR #200 already covers issue", str(ctx.exception))
 
     @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_reused_by_remote_branch(self, _auth, mock_api, _git_state):
-        mock_api.side_effect = [
+    def test_lock_issue_reused_by_remote_branch(self, _auth, _git_state):
+        self.mock_dup_fetcher.return_value = (
             [],
-            [{"name": "feat/issue-196-existing-work"}],
-        ]
+            ["feat/issue-196-existing-work"],
+            {"status": "not_claimed"},
+        )
         with self.assertRaises(ValueError) as ctx:
             gitea_lock_issue(issue_number=196, branch_name="feat/issue-196-mutations", remote="prgs")
-        self.assertIn("already has matching branch", str(ctx.exception))
+        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:
@@ -3284,6 +3379,28 @@ class TestIssueLocking(unittest.TestCase):
                 )
         self.assertIn("does not match locked worktree", 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_manual_lock_seed_blocked(self, _auth, _role):
+        with open(ISSUE_LOCK_FILE, "w", encoding="utf-8") as f:
+            json.dump(
+                _sample_issue_lock(
+                    issue_number=447,
+                    branch_name="feat/issue-447-lock-provenance",
+                    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",
+                )
+        self.assertIn("lock provenance", str(ctx.exception).lower())
+
     @patch("mcp_server.api_request")
     @patch("mcp_server.role_session_router.check_author_mutation_after_reviewer_stop",
            return_value=(True, []))

tests/test_review_proofs.py

@@ -2346,6 +2346,7 @@ class TestWorkIssueFinalReport(unittest.TestCase):
             "- Safe next action: open PR",
             "- Next: open PR",
             "- Safety statement: no review/merge",
+            "- Duplicate work outcome: duplicate work not prevented",
         ])
 
     def test_complete_work_issue_report_earns_a(self):

tests/test_webui_queue_dashboard.py

@@ -12,12 +12,14 @@ from starlette.testclient import TestClient
 from webui.app import create_app
 from webui.queue_loader import (
     PaginationMeta,
+    QueueSnapshot,
     _classify_issue,
     _classify_pr,
     _extract_linked_issue,
     load_queue_snapshot,
     snapshot_to_dict,
 )
+from webui.queue_views import render_queue_page
 
 _RECENT = datetime.now(timezone.utc).isoformat()
 _STALE = (datetime.now(timezone.utc) - timedelta(days=30)).isoformat()
@@ -210,5 +212,77 @@ class TestQueueRoutes(unittest.TestCase):
         self.assertEqual(len(snapshot.prs), 0)
 
 
+def _empty_pagination() -> PaginationMeta:
+    return PaginationMeta(
+        page=1,
+        per_page=50,
+        returned_count=0,
+        has_more=False,
+        is_final_page=True,
+        inventory_complete=True,
+        pages_fetched=1,
+    )
+
+
+def _empty_fetch(*_args, **_kwargs):
+    return [], _empty_pagination()
+
+
+class TestQueueFailClosedUx(unittest.TestCase):
+    """Regression tests for #458 fail-closed empty-state copy."""
+
+    def test_fail_closed_view_suppresses_empty_queue_copy(self):
+        snapshot = QueueSnapshot(
+            project_id="gitea-tools",
+            repo_label="Scaled-Tech-Consulting/Gitea-Tools",
+            prs=(),
+            issues=(),
+            pr_pagination=None,
+            issue_pagination=None,
+            fetch_error="Gitea credentials unavailable for gitea.prgs.cc",
+        )
+        html = render_queue_page(snapshot)
+        self.assertIn("Queue unavailable", html)
+        self.assertIn("Not loaded", html)
+        self.assertNotIn("No open items.", html)
+        self.assertIn("pagination:</strong> unavailable", html)
+
+    def test_fail_closed_route_does_not_show_empty_queue_copy(self):
+        client = TestClient(create_app())
+        snapshot = load_queue_snapshot(
+            fetch_prs=_empty_fetch,
+            fetch_issues=_empty_fetch,
+        )
+        snapshot = QueueSnapshot(
+            project_id=snapshot.project_id,
+            repo_label=snapshot.repo_label,
+            prs=(),
+            issues=(),
+            pr_pagination=None,
+            issue_pagination=None,
+            fetch_error="Gitea credentials unavailable for gitea.prgs.cc",
+        )
+        with mock.patch("webui.app.load_queue_snapshot", return_value=snapshot):
+            response = client.get("/queue")
+        self.assertEqual(response.status_code, 200)
+        self.assertIn("Queue unavailable", response.text)
+        self.assertNotIn("No open items.", response.text)
+
+    def test_successful_empty_inventory_shows_empty_copy(self):
+        snapshot = load_queue_snapshot(
+            fetch_prs=_empty_fetch,
+            fetch_issues=_empty_fetch,
+        )
+        self.assertIsNone(snapshot.fetch_error)
+        self.assertEqual(len(snapshot.prs), 0)
+        self.assertEqual(len(snapshot.issues), 0)
+        self.assertTrue(snapshot.pr_pagination.inventory_complete)
+
+        html = render_queue_page(snapshot)
+        self.assertNotIn("Queue unavailable", html)
+        self.assertEqual(html.count("No open items."), 2)
+        self.assertIn("pagination (complete)", html)
+
+
 if __name__ == "__main__":
     unittest.main()

webui/queue_views.py

@@ -38,7 +38,13 @@ def _queue_table(
     title: str,
     items: tuple[QueueItem, ...],
     columns: tuple[tuple[str, str], ...],
+    fetch_failed: bool = False,
 ) -> str:
+    if fetch_failed:
+        return (
+            f"<h3>{html.escape(title)}</h3>"
+            "<p class='muted'>Not loaded — queue fetch did not complete.</p>"
+        )
     if not items:
         return f"<h3>{html.escape(title)}</h3><p class='muted'>No open items.</p>"
 
@@ -73,9 +79,11 @@ def render_queue_page(snapshot: QueueSnapshot) -> str:
             f"{html.escape(snapshot.fetch_error)}</p></div>"
         )
 
+    fetch_failed = bool(snapshot.fetch_error)
     pr_section = _queue_table(
         title="Open pull requests",
         items=snapshot.prs,
+        fetch_failed=fetch_failed,
         columns=(
             ("number", "#"),
             ("title", "Title"),
@@ -88,6 +96,7 @@ def render_queue_page(snapshot: QueueSnapshot) -> str:
     issue_section = _queue_table(
         title="Open issues",
         items=snapshot.issues,
+        fetch_failed=fetch_failed,
         columns=(
             ("number", "#"),
             ("title", "Title"),