fix: resolve Next.js 16 build errors

- Extract Elysia app from route.ts into lib/api/app.ts to avoid
  Next.js 16 invalid export validation ('app' is not a valid route
  export field)
- Remove runtime='nodejs' from opengraph-image.tsx (invalid segment
  config in Next.js 16)
- Replace computed revalidate expression in sitemap.ts with literal
  (Next.js cannot statically evaluate BinaryExpression for segment
  configs)
- Update eden.ts imports to match new app.ts location

lib/api/app.ts

@@ -0,0 +1,125 @@
+import { Elysia } from "elysia"
+import { auth } from "@/lib/auth"
+import { rateLimit } from "@/lib/auth/rate-limit"
+import {
+  healthRoutes,
+  userRoutes,
+  gamesRoutes,
+  gameVersionsRoutes,
+  gameSyncRoutes,
+  hardwareRoutes,
+  hardwareStatsRoutes,
+  performanceRoutes,
+  performanceVerifyRoutes,
+  performanceSubmitRoutes,
+  commentsRoutes,
+  savedGamesRoutes,
+  reportRoutes,
+  contactRoutes,
+  adminReportRoutes,
+  adminPerformanceRoutes,
+  adminCommentRoutes,
+} from "@/lib/api"
+import { steamSearchRoutes } from "@/lib/api/steam-search"
+import { searchUnifiedRoutes } from "@/lib/api/search-unified"
+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 { steamReviewRoutes } from "@/lib/api/steam-reviews"
+import { communitySuggestionRoutes } from "@/lib/api/community-suggestions"
+import { gamesListingRoutes } from "@/lib/api/games-listing"
+import { steamgridProxyRoutes } from "@/lib/api/steamgrid-proxy"
+import { dashboardRoutes } from "@/lib/api/dashboard"
+import { savedFilterRoutes } from "@/lib/api/saved-filters"
+
+const betterAuth = new Elysia({ name: "better-auth" })
+  .mount(auth.handler)
+  .macro({
+    auth: {
+      async resolve({ status, request: { headers } }) {
+        const session = await auth.api.getSession({
+          headers,
+        })
+
+        if (!session) return status(401)
+
+        return {
+          user: session.user,
+          session: session.session,
+        }
+      },
+    },
+  })
+
+export const app = new Elysia({ prefix: "/api" })
+  .onError(({ code, error, set, request }) => {
+    console.error(
+      `[API Error] ${code} ${request.url}`,
+      error instanceof Error ? error.message : error,
+    )
+    set.status = code === "NOT_FOUND" ? 404 : 500
+    return {
+      error: code === "NOT_FOUND" ? "Not found" : "Internal server error",
+    }
+  })
+  .use(rateLimit(60, 100))
+  .use(betterAuth)
+  // Health
+  .use(healthRoutes)
+  // Users
+  .use(userRoutes)
+  // Games + Versions
+  .use(gamesRoutes)
+  .use(gameVersionsRoutes)
+  .use(gameSyncRoutes)
+  .use(gamesListingRoutes)
+  // Hardware
+  .use(hardwareRoutes)
+  .use(hardwareStatsRoutes)
+  // Performance
+  .use(performanceRoutes)
+  .use(performanceVerifyRoutes)
+  .use(performanceSubmitRoutes)
+  .use(reportRoutes)
+  .use(adminReportRoutes)
+  .use(adminPerformanceRoutes)
+  .use(adminCommentRoutes)
+  // Comments
+  .use(commentsRoutes)
+  // Steam search proxy
+  .use(steamSearchRoutes)
+  // Unified search
+  .use(searchUnifiedRoutes)
+  // Game stub creation
+  .use(gameStubRoutes)
+  // SteamGridDB proxy
+  .use(steamgridProxyRoutes)
+  // Game stats aggregation
+  .use(gameStatsRoutes)
+  // Manual game creation
+  .use(gamesManualRoutes)
+  // Saved games
+  .use(savedGamesRoutes)
+  // Contact form
+  .use(contactRoutes)
+  // Compare
+  .use(compareRoutes)
+  // Playability
+  .use(playabilityRoutes)
+  // Steam reviews
+  .use(steamReviewRoutes)
+  // Community suggestions
+  .use(communitySuggestionRoutes)
+  // Saved filters
+  .use(savedFilterRoutes)
+  // Dashboard
+  .use(dashboardRoutes)
+  // Root
+  .get("/", () => ({
+    name: "DeckyVault API",
+    version: "2026.0.9",
+  }))
+
+export type App = typeof app

lib/eden.ts

@@ -1,5 +1,5 @@
 import { treaty } from "@elysia/eden"
-import type { App } from "@/app/api/[[...slugs]]/route"
+import type { App } from "@/lib/api/app"
 
 // Use require() on the server branch to prevent the client bundler from
 // pulling in Elysia and the route module. The typeof window check is the
@@ -7,5 +7,5 @@ import type { App } from "@/app/api/[[...slugs]]/route"
 export const api =
   typeof window === "undefined"
     ? // eslint-disable-next-line @typescript-eslint/no-require-imports
-      treaty((require("../app/api/[[...slugs]]/route") as { app: App }).app).api
+      treaty((require("@/lib/api/app") as { app: App }).app).api
     : treaty<App>(process.env.NEXT_PUBLIC_SITE_URL || "http://localhost:3000").api