feat(android): add Capacitor setup for Android APK builds

- Migrate web assets from root to www/ directory
- Add Android native project with Capacitor 8
- Add GitHub Actions workflow for automated APK builds
- Configure app identity and splash screens

capacitor.config.ts

@@ -0,0 +1,15 @@
+import type { CapacitorConfig } from '@capacitor/cli';
+
+const config: CapacitorConfig = {
+  appId: 'es.dariosevilla.impostor',
+  appName: 'Juego del Impostor',
+  webDir: 'www',
+  server: {
+    androidScheme: 'https'
+  },
+  android: {
+    backgroundColor: '#0a0a0a'
+  }
+};
+
+export default config;