The duckdb library is already gone (not a dependency, not importable, no
`import duckdb` anywhere) — these were leftover text references that misled.
- Delete storage/schema.py: 418 lines of DuckDB DDL with zero importers. The
Postgres schema is created by db_pg._apply_schema + event_store._ensure_schema.
- Neutralise stale default db_path strings (./data/momentum*.duckdb) in
event_store, config, run_live_paper, dashboard_api — the connection layer
ignores the path (DATABASE_URL is the datastore), so these phantom file paths
only created confusion. Dropped the now-pointless os.makedirs for them.
- research/multi_schema: the "three DuckDB files" are one Postgres DB now (all
resolve to the same connection); doc + constants updated to match reality.
- Fix stale "DuckDB handle" comments in api/main.
Kept the DuckDB mentions in storage/db_pg.py + storage/db.py — they document
why the Postgres facade mimics DuckDB's ? placeholders and :memory: semantics.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>