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>