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

lib/api/games-listing.ts

@@ -51,9 +51,18 @@ export const gamesListingRoutes = new Elysia({ prefix: "/games/listing" }).get(
       )
     }
 
-    // Genre filter
+    // Genre filter (supports comma-separated list with OR logic)
     if (genre) {
-      conditions.push(sql`${games.genres} @> ${JSON.stringify([genre])}::jsonb`)
+      const genres = genre.split(",").filter(Boolean)
+      if (genres.length === 1) {
+        conditions.push(sql`${games.genres} @> ${JSON.stringify([genres[0]])}::jsonb`)
+      } else if (genres.length > 1) {
+        // OR logic: game matches ANY of the selected genres
+        const genreConditions = genres.map(
+          (g) => sql`${games.genres} @> ${JSON.stringify([g])}::jsonb`,
+        )
+        conditions.push(or(...genreConditions)!)
+      }
     }
 
     // Device filter
@@ -96,6 +105,8 @@ export const gamesListingRoutes = new Elysia({ prefix: "/games/listing" }).get(
         eq(performanceEntries.isRemoved, false),
         minFps ? gte(performanceEntries.fpsAvg, Number(minFps)) : undefined,
         maxFps ? lte(performanceEntries.fpsAvg, Number(maxFps)) : undefined,
+        // Scope to active device when device filter is set
+        device ? eq(performanceEntries.hardwareSlug, device) : undefined,
       ].filter((c): c is SQL => c !== undefined)
 
       const fpsSubquery = db