feat: implement ensure_publication for zero_publication management

- Added the ensure_publication function to create and verify the zero_publication if it is missing, ensuring idempotency during database initialization.
- Integrated ensure_publication into the create_db_and_tables function to prevent zero-cache crash loops on startup.
- Introduced a self-check script to validate the ensure_publication functionality on a create_all-bootstrapped database.
- Updated various components to reflect the transition from search space to workspace, including adjustments in imports and routing paths.

surfsense_backend/scripts/check_zero_publication_bootstrap.py

@@ -0,0 +1,46 @@
+"""Self-check for ensure_publication on a create_all-bootstrapped scratch DB."""
+
+import asyncio
+
+import asyncpg
+from sqlalchemy import text
+from sqlalchemy.ext.asyncio import create_async_engine
+
+SCRATCH_DB = "surfsense_zero_pub_check"
+ADMIN_DSN = "postgresql://postgres:postgres@localhost:5432/postgres"
+SCRATCH_URL = f"postgresql+asyncpg://postgres:postgres@localhost:5432/{SCRATCH_DB}"
+
+
+async def main() -> None:
+    admin = await asyncpg.connect(ADMIN_DSN)
+    await admin.execute(f'DROP DATABASE IF EXISTS "{SCRATCH_DB}" WITH (FORCE)')
+    await admin.execute(f'CREATE DATABASE "{SCRATCH_DB}"')
+    await admin.close()
+
+    from app.db import Base
+    from app.zero_publication import ensure_publication, verify_publication
+
+    engine = create_async_engine(SCRATCH_URL)
+    try:
+        async with engine.begin() as conn:
+            await conn.execute(text("CREATE EXTENSION IF NOT EXISTS vector"))
+            await conn.execute(text("CREATE EXTENSION IF NOT EXISTS pg_trgm"))
+            await conn.run_sync(Base.metadata.create_all)
+            await conn.run_sync(ensure_publication)
+            mismatches = await conn.run_sync(verify_publication)
+            assert not mismatches, f"shape wrong after ensure: {mismatches}"
+
+            # Second call must be a no-op that leaves a verified shape.
+            await conn.run_sync(ensure_publication)
+            mismatches = await conn.run_sync(verify_publication)
+            assert not mismatches, f"shape wrong after re-ensure: {mismatches}"
+    finally:
+        await engine.dispose()
+        admin = await asyncpg.connect(ADMIN_DSN)
+        await admin.execute(f'DROP DATABASE IF EXISTS "{SCRATCH_DB}" WITH (FORCE)')
+        await admin.close()
+
+    print("OK: ensure_publication creates and verifies on a create_all DB, idempotently.")
+
+
+asyncio.run(main())