b6770d394c
Collapse the game UI to one route (`/`): a screen dispatcher renders login/lobby/lobby-create/game from `appScreen`/`activeView` state instead of URL routes. Move screen components to lib/screens & lib/game; the game shell reads the game id from `appScreen.gameId` and re-inits per-game stores via an $effect; in-game views render from `activeView`. Flip ~23 goto/href nav sites to store mutations; drop the `?sidebar=` URL coupling. Auth gate is now state-based. WIP: browser-history (Back→lobby), restore-validation, the return-to-lobby button, push deep-links, and the test migration are follow-ups on this branch. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>