feat(engineering): enforce V1-0 write invariants

src/atocore/models/database.py

@@ -146,6 +146,28 @@ def _apply_migrations(conn: sqlite3.Connection) -> None:
         "CREATE INDEX IF NOT EXISTS idx_memories_graduated ON memories(graduated_to_entity_id)"
     )
 
+    # V1-0 (Engineering V1 completion): shared header fields per
+    # engineering-v1-acceptance.md:45. Three columns on `entities`:
+    # - extractor_version: which extractor produced this row. Lets old
+    #   candidates be re-evaluated with a newer extractor per
+    #   promotion-rules.md:268.
+    # - canonical_home: which layer holds the canonical record. Always
+    #   "entity" for rows written via create_entity; reserved for future
+    #   cross-layer bookkeeping.
+    # - hand_authored: 1 when the row was created directly by a human
+    #   without source provenance. Enforced by the write path so every
+    #   non-hand-authored row must carry non-empty source_refs (F-8).
+    # The entities table itself is created by init_engineering_schema
+    # (see engineering/service.py); these ALTERs cover existing DBs
+    # where the original CREATE TABLE predates V1-0.
+    if _table_exists(conn, "entities"):
+        if not _column_exists(conn, "entities", "extractor_version"):
+            conn.execute("ALTER TABLE entities ADD COLUMN extractor_version TEXT DEFAULT ''")
+        if not _column_exists(conn, "entities", "canonical_home"):
+            conn.execute("ALTER TABLE entities ADD COLUMN canonical_home TEXT DEFAULT 'entity'")
+        if not _column_exists(conn, "entities", "hand_authored"):
+            conn.execute("ALTER TABLE entities ADD COLUMN hand_authored INTEGER DEFAULT 0")
+
     # Phase 4 (Robustness V1): append-only audit log for memory mutations.
     # Every create/update/promote/reject/supersede/invalidate/reinforce/expire/
     # auto_promote writes one row here. before/after are JSON snapshots of the
@@ -352,6 +374,14 @@ def _column_exists(conn: sqlite3.Connection, table: str, column: str) -> bool:
     return any(row["name"] == column for row in rows)
 
 
+def _table_exists(conn: sqlite3.Connection, table: str) -> bool:
+    row = conn.execute(
+        "SELECT name FROM sqlite_master WHERE type='table' AND name=?",
+        (table,),
+    ).fetchone()
+    return row is not None
+
+
 @contextmanager
 def get_connection() -> Generator[sqlite3.Connection, None, None]:
     """Get a database connection with row factory."""