portrait: lock orientation + portrait-optimized felt table

- Lock the app to portrait: AndroidManifest screenOrientation="portrait" and PWA
  manifest orientation "portrait".
- GameTable felt now occupies the middle band (between top HUD and the hand) with
  portrait proportions (w<=560, tall) so the you/partner/opponents diamond fits a
  tall screen comfortably instead of a wide landscape ellipse.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

public/manifest.webmanifest

@@ -7,7 +7,7 @@
   "start_url": "/",
   "display": "fullscreen",
   "display_override": ["fullscreen", "standalone", "minimal-ui"],
-  "orientation": "any",
+  "orientation": "portrait",
   "background_color": "#060c1f",
   "theme_color": "#060c1f",
   "icons": [