fix(scope): wire author bootstrap scope into workflow scope guard (Closes #941)

PR #926 (#892) taught create_issue_bootstrap.bootstrap_permits_control_checkout
to accept task_scope=author_issue_bootstrap and wired that canonical decision
into the #274 branches-only enforcer and the #604 anti-stomp preflight. A third
enforcement path was left unwired.

workflow_scope_guard kept its own copy of the clean-root author decision, gated
on create_issue_bootstrap.is_create_issue_task -- a task-name allowlist that
never contained bootstrap_author_issue_worktree. The real call path

    gitea_bootstrap_author_issue_worktree
      -> verify_preflight_purity
        -> _enforce_issue_scope_guard
          -> workflow_scope_guard.assess_production_mutation_guards

therefore raised ProductionGuardError(missing_issue_worktree) before
assess_author_issue_bootstrap was ever consulted, leaving the #892 deadlock
partially present and blocking issue #931.

Changes:

* workflow_scope_guard.assess_root_source_mutation accepts the server-derived
  bootstrap_assessment and, for the clean-root author case, consults the
  canonical bootstrap_permits_control_checkout decision instead of a local
  task-name allowlist. The create_issue arm is unchanged.
* workflow_scope_guard.assess_production_mutation_guards forwards the evidence.
* _enforce_issue_scope_guard accepts and threads the same assessment the #274
  and #604 guards already consume, so all three judge identical evidence, and
  waives the pre-ownership issue-lock requirement for the bootstrap task via
  that same canonical decision rather than a second task-name allowlist.
* verify_preflight_purity passes the once-computed assessment at both sites.

The waiver cannot widen: the predicate fails closed on missing, malformed,
cross-scope, dirty, drifted, or wrongly bound evidence, so ordinary author
source and test mutation from the control checkout stays forbidden and the
#274/#604/#618/#683 protections are unchanged.

Regression: tests/test_issue_941_scope_guard_bootstrap_wiring.py drives the
real enforcer rather than the authorization helper in isolation, which is why
#892's own predicate tests passed while the live bootstrap stayed blocked.

Closes #941

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

gitea_mcp_server.py

@@ -1546,6 +1546,7 @@ def verify_preflight_purity(
             task=task,
             target_issue_number=target_issue_number,
             require_author_lock=require_author_lock,
+            bootstrap_assessment=bootstrap_assessment,
         )
         # #604: common anti-stomp preflight after legacy + #683 enforcers.
         _run_anti_stomp_preflight(
@@ -1585,6 +1586,7 @@ def verify_preflight_purity(
             task=task,
             target_issue_number=target_issue_number,
             require_author_lock=require_author_lock,
+            bootstrap_assessment=bootstrap_assessment,
         )
         if force_anti_stomp:
             _run_anti_stomp_preflight(
@@ -1652,8 +1654,15 @@ def _enforce_issue_scope_guard(
     task: str | None = None,
     target_issue_number: int | None = None,
     require_author_lock: bool = False,
+    bootstrap_assessment: object = _BOOTSTRAP_UNSET,
 ) -> None:
-    """#683: fail closed on missing/out-of-scope issue ownership for mutations."""
+    """#683: fail closed on missing/out-of-scope issue ownership for mutations.
+
+    #941: the shared bootstrap assessment is threaded in so this guard judges
+    the author issue-worktree bootstrap on the same server-derived evidence as
+    the #274 branches-only and #604 anti-stomp guards. Callers that supply
+    none fall back to computing it here, which preserves behaviour.
+    """
     ctx = _resolve_namespace_mutation_context(worktree_path)
     workspace = ctx["workspace_path"]
     git_state = issue_lock_worktree.read_worktree_git_state(workspace)
@@ -1703,11 +1712,32 @@ def _enforce_issue_scope_guard(
     import create_issue_bootstrap as _cib
 
     is_create_issue = _cib.is_create_issue_task(task)
+    # #941: consume the caller-computed bootstrap assessment when one was
+    # threaded in, so this guard and the #274/#604 guards judge identical
+    # evidence. Falling back preserves behaviour for callers that supply none.
+    bootstrap = (
+        _create_issue_bootstrap_assessment(task, worktree_path)
+        if bootstrap_assessment is _BOOTSTRAP_UNSET
+        else bootstrap_assessment
+    )
+    # #941: the author issue-worktree bootstrap is pre-ownership for the same
+    # reason create_issue is — it exists to break the lock<->worktree cycle, so
+    # no owning lock can exist yet. The exemption is granted by the canonical
+    # shared decision over server-derived evidence, never by a task-name list,
+    # and fails closed on missing, malformed, cross-scope, dirty, drifted, or
+    # wrongly bound evidence.
+    bootstrap_waives_ownership = _cib.bootstrap_permits_control_checkout(
+        bootstrap,
+        task=task,
+        workspace_path=workspace,
+        canonical_repo_root=ctx["canonical_repo_root"],
+    )
     require_lock = bool(require_author_lock) or (
         authorish
         and workflow_scope_guard.production_guards_forced()
         and role == "author"
         and not is_create_issue
+        and not bootstrap_waives_ownership
     )
     assessment = workflow_scope_guard.assess_production_mutation_guards(
         workspace_path=workspace,
@@ -1720,6 +1750,7 @@ def _enforce_issue_scope_guard(
         require_author_lock=require_lock,
         in_test_mode=_preflight_in_test_mode(),
         mutation_task=task,
+        bootstrap_assessment=bootstrap,
     )
     workflow_scope_guard.raise_if_blocked(assessment)