feat(core,backends,frontends,storage): conversations, inject queue, session pool, gateway mcp tools, api frontend

tests/test_db_migrate.py

@@ -31,3 +31,31 @@ async def test_create_all_adds_missing_columns() -> None:
         session.add(conv)
         await session.commit()
     await db.dispose()
+
+
+async def test_create_all_backfills_defaults_for_old_rows() -> None:
+    path = Path(tempfile.mkdtemp(prefix="beaver-migrate-")) / "old.db"
+    raw = sqlite3.connect(path)
+    raw.execute(
+        "CREATE TABLE conversations (id INTEGER PRIMARY KEY, frontend VARCHAR NOT NULL, "
+        "external_id VARCHAR NOT NULL, agent_name VARCHAR NOT NULL, session_id VARCHAR, "
+        "created_at DATETIME NOT NULL, updated_at DATETIME NOT NULL)"
+    )
+    raw.execute(
+        "INSERT INTO conversations VALUES (1, 'markdown', 'x', 'a', NULL, '2026-01-01', '2026-01-01')"
+    )
+    raw.commit()
+    raw.close()
+
+    db = Database(f"sqlite:///{path}")
+    await db.create_all()
+    async with db.session() as session:
+        conv = (await session.exec(select(Conversation))).one()
+        assert (conv.kind, conv.status, conv.pending_question, conv.flags) == (
+            "deep",
+            "open",
+            False,
+            {},
+        )
+        assert conv.running_turn is None
+    await db.dispose()