feat: sitemap remediation, PWA activation, search refinements, Steam Deck UX

Sitemap:
- Switch from ISR (revalidate=3600) to force-dynamic for per-request generation
- Flatten into single app/sitemap.ts with inlined static entries and DB queries
- NULL-safe syncStatus filter: ne(games.syncStatus, 'failed') OR isNull(games.syncStatus)
- Structured JSON logging for generated URLs and DB errors
- Delete lib/sitemap/* helpers and app/api/revalidate-sitemap route
- Add basic vitest coverage for sitemap exports

PWA & Offline:
- Add @serwist/next service worker (webpack build) with runtime caching
- Cache strategies: stale-while-revalidate for game pages, network-first for listings/API,
  cache-first for Steam CDN images
- Offline fallback page (public/offline.html)
- Manifest icons: 192px maskable + 512px any
- Viewport meta with viewport-fit=cover, user-scalable=no
- Apple mobile web app meta tags

Search / Filter Refinements:
- Multi-genre OR support in listing API (comma-separated genres)
- Device-scoped FPS filter (min/max FPS constrained to selected device)
- Client-side URL state sync via router.replace for shareable filtered views
- Initialize filter state from URL params on mount
- Auto-collapse filter panel on saved-filter load
- Fix multi-genre saved filter parsing (comma-separated)

Steam Deck / Touch / Gamepad UX:
- WCAG 2.1 AA touch targets (44x44px) on all filter controls
- .gamepad-focus CSS focus ring for controller navigation
- useGamepadNavigation hook: D-pad/left-stick roving tabindex, A/B/X/Y actions
- Integrate gamepad hook into games page (X=search, Y=toggle filters)

Chore:
- Bump version to 2026.0.97

package.json

@@ -1,10 +1,10 @@
 {
   "name": "deckyvault",
-  "version": "2026.0.96",
+  "version": "2026.0.97",
   "private": true,
   "scripts": {
-    "dev": "next dev --experimental-https",
-    "build": "next build",
+    "dev": "next dev --experimental-https --webpack",
+    "build": "next build --webpack",
     "start": "next start",
     "lint": "eslint",
     "db:generate": "drizzle-kit generate",
@@ -20,6 +20,12 @@
     "@better-auth/drizzle-adapter": "^1.6.9",
     "@better-auth/passkey": "^1.6.9",
     "@elysia/eden": "^1.4.10",
+    "@serwist/expiration": "^9.5.11",
+    "@serwist/next": "^9.5.11",
+    "@serwist/precaching": "^9.5.11",
+    "@serwist/routing": "^9.5.11",
+    "@serwist/strategies": "^9.5.11",
+    "@serwist/sw": "^9.5.11",
     "@tiptap/core": "^3.22.4",
     "@tiptap/extension-link": "^3.22.4",
     "@tiptap/extension-placeholder": "^3.22.4",
@@ -46,6 +52,7 @@
     "remark": "^15.0.1",
     "remark-rehype": "^11.1.2",
     "resend": "^6.12.2",
+    "serwist": "^9.5.11",
     "web-haptics": "^0.0.6"
   },
   "devDependencies": {