Add a persistent "announced" checkbox after each track's Announce button.
The state is stored in a new `announced` column on `show_tracks` and is
auto-set when the Announce button is pressed. The checkbox is also freely
togglable, and announced tracks have their Announce button disabled.
Also fixes .env leakage in test_config.py (pass _env_file=None) and adds
tests for the new DB method, API endpoint, and announce side-effect.
Made-with: Cursor
Allows looking up shows by episode number instead of internal DB ID,
enabling IRC bot commands like !playlist 530 to resolve directly.
Made-with: Cursor
Adds a --init mode that seeds the database with past shows from a given
anchor episode/date forward, batch-fetching likes from SoundCloud and
partitioning them into weekly buckets. Episode numbers are tracked in
the shows table and auto-incremented by the poller for new shows.
Includes full API documentation (docs/api.md) and updated README.
Made-with: Cursor
