Sig select: _card-deck.scss extract, WS cursor fixes, own-role indicators, role icon refresh

- New _card-deck.scss: sig select styles moved out of _room.scss + _game-kit.scss
- sig-select.js: 3 WS bug fixes — thumbs-up deferred to window.load (layout settled
  before getBoundingClientRect), hover cursor cleared for all cards on reservation
  (not just the reserved card), applyHover guards against already-reserved roles
- Own-role indicators: gamer now sees their own role-coloured card outline + thumbs-up
- Reservation glow: replaced blurry role+ninUser double-shadow with crisp 2px outline
- Gravity qualifier: Graven text set to --terUser (matches Leavened/--quiUser pattern)
- Role card SVGs refreshed; starter-role-Blank removed
- FTs + Jasmine specs extended for sig select WS behaviour
- setup_sig_session management command for multi-browser manual testing

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/static_src/scss/core.scss

@@ -6,6 +6,7 @@
 @import 'gameboard';
 @import 'palette-picker';
 @import 'room';
+@import 'card-deck';
 @import 'tray';
 @import 'billboard';
 @import 'game-kit';