fix(validator): align final-report validator with canonical schema (Closes #698)

Fixes the final-report validator defects from Issue #698 (original lead
plus the independent reproduction recorded during the PR #703 formal
review, comment 11246):

- Legacy fields: the review/merger required-field tables no longer demand
  'Pinned reviewed head', 'Scratch worktree used', 'Worktree path',
  'Worktree dirty', 'Mutations', 'Next', 'Issue/PR', 'Branch/SHA', or
  'Files changed' — names the canonical review-merge-final-report schema
  forbids or replaces. The canonical names ('Reviewed head SHA', 'Review
  worktree path/dirty', 'Safe next action', mutation categories) are
  required instead, with backward-compatible aliases where the schema
  permits them.
- Structured proof: workflow-load helper results are recognized in
  colon, key=value, and JSON renderings; validation pass proof is
  accepted anywhere in the Validation field value (for example
  'focused 50 passed; full 2665 passed').
- Mutation inference: review mutations are inferred only from
  authoritative evidence (performed=true and not gated); read-only
  diagnostics and pre-API rejections no longer count as mutations.
- Lease release vs cleanup: canonical reviewer lease release (release
  tool call or terminal phase=released marker) is lease lifecycle, not
  post-merge cleanup, and no longer triggers the branch/worktree cleanup
  checklist; genuine delete/remove claims still require full proof.
- Blocked reports: a legitimately blocked run that states an explicit
  'Reviewed/Candidate head SHA: none' with no verdict, merge, or started
  validation owes no head proofs; approval-time and merge-time live-head
  proofs are demanded only once the corresponding phase begins, and a
  report that states no head at all still fails closed.
- action_log robustness: malformed (non-dict) entries and non-list logs
  are reported as clear sanitized findings (position and type only, no
  content echo) instead of crashing with AttributeError; a defective
  validator rule now fails closed with a sanitized block finding rather
  than raising a secondary exception.

27 new regression tests, including canonical fixtures modeled on the
PR #703 formal-review handoff and the blocked preflight report from the
prior #698 reproductions. Two legacy-field test fixtures updated to the
canonical schema. Full suite: 2663 passed, 6 skipped, 161 subtests.

Co-Authored-By: Claude Fable 5 <[email protected]>

review_proofs.py

@@ -858,9 +858,16 @@ _WALKTHROUGH_ARTIFACT_RE = re.compile(r"walkthrough\.md", re.I)
 
 
 def _performed_file_mutations(action_log: list[dict] | None) -> list[dict]:
-    """Return performed local file mutations, excluding gated rejections."""
+    """Return performed local file mutations, excluding gated rejections.
+
+    Non-dict entries (malformed JSON, LLM mistakes) are ignored instead of
+    raising ``AttributeError`` (#698): a malformed ledger entry can never be
+    authoritative mutation evidence.
+    """
     performed: list[dict] = []
     for entry in action_log or []:
+        if not isinstance(entry, dict):
+            continue
         if entry.get("gated_rejected") or entry.get("performed") is False:
             continue
         action = (entry.get("action") or "").strip().lower()
@@ -2228,24 +2235,31 @@ HANDOFF_REVIEW_MUTATION_FIELDS = (
 )
 
 HANDOFF_ROLE_FIELDS = {
+    # #698: the review/merger required-field sets must stay aligned with the
+    # canonical schema (skills/llm-project-workflow/schemas/
+    # review-merge-final-report.md). The schema explicitly FORBIDS the legacy
+    # fields 'Pinned reviewed head', 'Scratch worktree used', and 'Workspace
+    # mutations' — a validator must never demand a field the schema bans.
     "review": (
         ("Selected PR", ("selected pr",)),
         ("Reviewer eligibility", ("reviewer eligibility", "eligibility")),
-        ("Pinned reviewed head", ("pinned reviewed head", "pinned head")),
-        ("Worktree path", ("worktree path", "starting worktree path")),
-        ("Worktree dirty", ("worktree dirty", "whether worktree was dirty")),
-        ("Scratch worktree used", ("scratch worktree used", "scratch clone used",
-                                   "scratch worktree")),
+        ("Reviewed head SHA", ("reviewed head sha", "candidate head sha")),
+        ("Review worktree path", ("review worktree path", "worktree path",
+                                  "starting worktree path")),
+        ("Review worktree dirty", ("review worktree dirty", "worktree dirty",
+                                   "whether worktree was dirty")),
         ("Unrelated local mutations", ("unrelated local mutations",
-                                       "unrelated files modified")),
+                                       "unrelated files modified",
+                                       "file edits by reviewer")),
         ("Review decision", ("review decision", "decision")),
         ("Merge result", ("merge result",)),
         ("Linked issue status", ("linked issue status", "linked issue")),
         ("Cleanup status", ("cleanup status", "cleanup")),
+        ("Safe next action", ("safe next action", "next")),
     ) + HANDOFF_REVIEW_MUTATION_FIELDS,
     "merger": (
         ("Selected PR", ("selected pr",)),
-        ("Pinned reviewed head", ("pinned reviewed head", "pinned head")),
+        ("Reviewed head SHA", ("reviewed head sha", "candidate head sha")),
         ("Active profile", ("active profile",)),
         ("Role kind", ("role kind",)),
         ("Merge capability source", ("merge capability source",)),
@@ -2433,9 +2447,22 @@ def assess_controller_handoff(report_text, role=None, local_edits=False):
         # Issue #320: reviewer and merger handoffs use the precise mutation categories
         # in HANDOFF_REVIEW_MUTATION_FIELDS instead of the legacy ambiguous
         # "Workspace mutations" field, which is rejected below.
+        # Issue #698: the canonical review-merge schema has no 'Mutations',
+        # 'Next', 'Issue/PR', 'Branch/SHA', or 'Files changed' fields — their
+        # content lives in the precise mutation categories, 'Safe next
+        # action', 'Selected PR'/'Linked issue', head-SHA fields, and 'Files
+        # reviewed'. Requiring the legacy names rejects canonical reports.
+        _non_canonical_for_review = {
+            "Workspace mutations",
+            "Mutations",
+            "Next",
+            "Issue/PR",
+            "Branch/SHA",
+            "Files changed",
+        }
         required = [
             field for field in required
-            if field[0] != "Workspace mutations"
+            if field[0] not in _non_canonical_for_review
         ]
         if any(label.startswith("workspace mutations") for label in labels):
             return {