feat(engineering): V1-0 write-time invariants (F-1 + F-5 hook + F-8)

Phase V1-0 of the Engineering V1 Completion Plan. Establishes the
write-time invariants every later phase depends on so no later phase
can leak invalid state into the entity store.

F-1 shared-header fields per engineering-v1-acceptance.md:45:
  - entities.extractor_version (default "", EXTRACTOR_VERSION="v1.0.0"
    written by service.create_entity)
  - entities.canonical_home (default "entity")
  - entities.hand_authored (default 0, INTEGER boolean)
  Idempotent ALTERs in both _apply_migrations (database.py) and
  init_engineering_schema (service.py). CREATE TABLE also carries the
  columns for fresh DBs. _row_to_entity tolerates old rows without
  them so tests that predate V1-0 keep passing.

F-8 provenance enforcement per promotion-rules.md:243:
  create_entity raises ValueError when source_refs is empty and
  hand_authored is False. New kwargs hand_authored and
  extractor_version threaded through the API (EntityCreateRequest)
  and the /wiki/new form body (human wiki writes set hand_authored
  true by definition). The non-negotiable invariant: every row either
  carries provenance or is explicitly flagged as hand-authored.

F-5 synchronous conflict-detection hook on active create per
engineering-v1-acceptance.md:99:
  create_entity(status="active") now runs detect_conflicts_for_entity
  with fail-open per conflict-model.md:256. Detector errors log a
  warning but never 4xx-block the write (Q-3 "flag, never block").

Doc note added to engineering-ontology-v1.md recording that `project`
IS the `project_id` per "fields equivalent to" wording. No storage
rename.

Backfill script scripts/v1_0_backfill_provenance.py reports and
optionally flags existing active entities that lack provenance.
Idempotent. Supports --dry-run and --invalidate-instead.

Tests: 10 new in test_v1_0_write_invariants.py covering F-1 fields,
F-8 raise + bypass, F-5 hook on active + no-hook on candidate, Q-3
fail-open, Q-4 partial scope_only=active excludes candidates.

Three pre-existing conflict tests adapted to read list_open_conflicts
rather than re-run the detector (which now dedups because the hook
already fired at create-time). One API test adds hand_authored=true
since its fixture has no source_refs.

conftest.py wraps create_entity so tests that don't pass source_refs
or hand_authored default to hand_authored=True (tests author their
own fixture data — reasonable default). Production paths (API route,
wiki form, graduation scripts) all pass explicit values and are
unaffected.

Test count: 533 -> 543 (+10). Full suite green in 77.86s.

Pending: Codex review on the branch before squash-merge to main.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

tests/conftest.py

@@ -16,6 +16,36 @@ os.environ["ATOCORE_DATA_DIR"] = _default_test_dir
 os.environ["ATOCORE_DEBUG"] = "true"
 
 
+# V1-0: every entity created in a test is "hand authored" by the test
+# author — fixture data, not extracted content. Rather than rewrite 100+
+# existing test call sites, wrap create_entity so that tests which don't
+# provide source_refs get hand_authored=True automatically. Tests that
+# explicitly pass source_refs or hand_authored are unaffected. This keeps
+# the F-8 invariant enforced in production (the API, the wiki form, and
+# graduation scripts all go through the unwrapped function) while leaving
+# the existing test corpus intact.
+def _patch_create_entity_for_tests():
+    from atocore.engineering import service as _svc
+
+    _original = _svc.create_entity
+
+    def _create_entity_test(*args, **kwargs):
+        # Only auto-flag when hand_authored isn't explicitly specified.
+        # Tests that want to exercise the F-8 raise path pass
+        # hand_authored=False explicitly and should hit the error.
+        if (
+            not kwargs.get("source_refs")
+            and "hand_authored" not in kwargs
+        ):
+            kwargs["hand_authored"] = True
+        return _original(*args, **kwargs)
+
+    _svc.create_entity = _create_entity_test
+
+
+_patch_create_entity_for_tests()
+
+
 @pytest.fixture
 def tmp_data_dir(tmp_path):
     """Provide a temporary data directory for tests."""