Adds a modifier profile picker next to the layout picker in the Lobby, and a header badge in GameView that surfaces the active profile's name.
Lobby:
- New <select data-testid="profile-picker"> loads entries from loadLibrary() on mount and refreshes when the ModifierProfileEditor closes (auto-selecting the most recently updated entry).
- Selecting a saved profile sets the active ModifierProfile; selecting 'Custom…' opens the existing editor modal.
- URL param ?modifierProfile=<b64> decodes + pre-selects even when the profile isn't in the local library, via a synthetic '<name> (from link)' option so the <select> can reflect the choice without collapsing it.
- handleCreate now sends payload.profile when a profile is selected and stashes modifier-profile-name in sessionStorage.
- handleJoin reads profile from the server's room.joined echo so late joiners see the badge on first paint.
GameView:
- New ModifierProfileBadge component mirrors LayoutBadge but reads modifier-profile-name from sessionStorage and uses fuchsia tones so it's visually distinct when both badges are present.
lobby-request.ts:
- OneShotRoomResult exposes the optional profile field the server now echoes (T19).
E2E:
- 2 new Playwright tests: 'create room with profile — badge shows in game' seeds the library via localStorage, selects the profile, creates the room, and asserts the badge text. 'URL pre-select loads profile in picker' base64-encodes a profile into ?modifierProfile= and verifies the picker shows the correct value + 'from link' synthetic label.
All 8 modifier-profiles e2e tests pass; bun run check green (1213/1213 unit tests).