The game screen now drives a local vs_ai game through the offline engine, dispatched by
game id — completing the playable local game (on top of the source, #193). Online play
is unchanged.
- gamesource.ts: gameSource(id) returns the local source for a `local:` id, else the
gateway (the same game-loop interface). The offline engine stays OUT of the app entry
bundle — it is dynamically imported on first use (a separate chunk), so online-only
users never pay for it (the app entry stays within its size budget).
- localgame/id.ts: the tiny id helper (no engine imports) the dispatcher branches on.
- Game.svelte: the game-loop calls (state/history/submit/pass/exchange/resign/hint/
evaluate/draft) go through gameSource(id) instead of the gateway directly; a local
game's robot-reply events route through the same app event hub the network stream
feeds, so the screen reacts to opponent_moved / game_over identically.
Behaviour-preserving for network games (gameSource returns the gateway for them). Local
verify green: check + test:unit + build + bundle-size gate + e2e (196 passed).