feat: new "card fan" app icon — web favicon/PWA + Android adaptive

- Master SVGs + generator in scripts/icon/ (icon.svg full design, icon-foreground.svg
  cards-only for the Android adaptive layer, gen-icons.mjs via sharp).
- Web/PWA: regenerated favicon.ico (16/32/48), src/app/apple-icon.png, public/icon.svg,
  icon-192/512, icon-maskable-512; manifest now lists png + maskable icons.
- Android (Capacitor): ic_launcher / ic_launcher_round / ic_launcher_foreground for all
  densities + ic_launcher-playstore 512; adaptive background switched from flat white
  to a navy radial-gradient drawable (matches the icon), foreground = the gold card fan.

Design: navy field, gold rounded frame, three fanned cards with a gold spade —
on-brand with the in-app "Persian luxury" look.

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

public/manifest.webmanifest

@@ -11,11 +11,9 @@
   "background_color": "#060c1f",
   "theme_color": "#060c1f",
   "icons": [
-    {
-      "src": "/icon.svg",
-      "sizes": "any",
-      "type": "image/svg+xml",
-      "purpose": "any maskable"
-    }
+    { "src": "/icon.svg", "sizes": "any", "type": "image/svg+xml", "purpose": "any" },
+    { "src": "/icon-192.png", "sizes": "192x192", "type": "image/png", "purpose": "any" },
+    { "src": "/icon-512.png", "sizes": "512x512", "type": "image/png", "purpose": "any" },
+    { "src": "/icon-maskable.png", "sizes": "512x512", "type": "image/png", "purpose": "maskable" }
   ]
 }