fix(harness): ship coherent vendor harness cluster

Rebuild PR C to ship the vendor/photocraft harness as a coherent unit
(vendor implementation + vendor tests) instead of a per-file ahead/behind
mix that produced broken imports and 6+ test failures.

- Flip 36 harness impl/route/test files back to vendor (the per-file
  line-set policy misclassified user-rewritten files as 'behind').
- Flip core/models.py + src/tool_approval_scopes.py to vendor: vendor's
  harness (authority.py, turn_contract.py, clean_agent_preview.py) depends
  on vendor's older approval-scope API; upstream added
  CHAT_SESSION_APPROVAL_SIGNATURE_FIELD that vendor's core/models.py lacks.
- Add src/shutdown.py (new vendor infra) required by routes/chat_routes.py.
- Keep src/agent_tools/__init__.py at upstream (editor_tools registration
  lives in PR B).

Upstream-only security divergence preserved in C_upstream_delta.patch and
flagged for integration-time reconciliation.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

services/memory/memory_extractor.py

@@ -610,9 +610,7 @@ async def update_persona_memory(
         )
 
         updated = strip_think(str(raw or ""), prose=True, prompt_echo=True).strip()
-        # No leading `\s*` before the closing fence: .strip() drops that
-        # whitespace anyway, and scanning it from every offset was quadratic.
-        updated = re.sub(r"^```(?:text|markdown)?\s*|```$", "", updated, flags=re.I | re.S).strip()
+        updated = re.sub(r"^```(?:text|markdown)?\s*|\s*```$", "", updated, flags=re.I | re.S).strip()
         if len(updated) > 6000:
             updated = updated[:6000].rstrip()
         if updated == existing_memory:
@@ -696,9 +694,8 @@ async def audit_memories(
         # Parse the JSON list, tolerating reasoning-model noise: <think> blocks,
         # markdown fences, leading prose, and trailing commas.
         import re as _re
-        from src.text_helpers import strip_closed_think_blocks
         text = (raw or "").strip()
-        text = strip_closed_think_blocks(text).strip()
+        text = _re.sub(r'<think(?:ing)?>[\s\S]*?</think(?:ing)?>', '', text, flags=_re.I).strip()
 
         def _loads_list(s):
             if not s:
@@ -714,9 +711,7 @@ async def audit_memories(
 
         cleaned = _loads_list(text)
         if cleaned is None:
-            # Possessive `\s*+`: handing fence whitespace back to the body on a
-            # missing closing fence only rescanned the same tail (ReDoS).
-            _m = _re.search(r'```(?:json)?\s*+\n?([\s\S]*?)```', text)
+            _m = _re.search(r'```(?:json)?\s*\n?([\s\S]*?)```', text)
             if _m:
                 cleaned = _loads_list(_m.group(1).strip())
         if cleaned is None: