feat: add playability calculation API

- Auto-calculate playability from benchmark data (FPS, anti-cheat, upscaler dependency)
- Manual override by admins/contributors
- Clear override to revert to auto-calculated
- Three endpoints: /calculate/:gameId, /override/:gameId, /clear-override/:gameId
- Calculation logic: great (≥55 FPS, no upscaler), playable (≥30 FPS), needs_tweaks (≥20 FPS), unplayable (<20 FPS or anti-cheat unsupported)

app/api/[[...slugs]]/route.ts

@@ -26,6 +26,7 @@ import { gameStubRoutes } from "@/lib/api/game-stub"
 import { gameStatsRoutes } from "@/lib/api/game-stats"
 import { gamesManualRoutes } from "@/lib/api/games-manual"
 import { compareRoutes } from "@/lib/api/compare"
+import { playabilityRoutes } from "@/lib/api/playability"
 import { gamesListingRoutes } from "@/lib/api/games-listing"
 import { steamgridProxyRoutes } from "@/lib/api/steamgrid-proxy"
 
@@ -101,6 +102,8 @@ export const app = new Elysia({ prefix: "/api" })
   .use(contactRoutes)
   // Compare
   .use(compareRoutes)
+  // Playability
+  .use(playabilityRoutes)
   // Root
   .get("/", () => ({
     name: "DeckyVault API",