Upgrade website to Next.js 16

apps/website/AGENTS.md

@@ -0,0 +1,9 @@
+<!-- BEGIN:nextjs-agent-rules -->
+
+# This is NOT the Next.js you know
+
+This version has breaking changes — APIs, conventions, and file structure may all differ from your training data. Read the relevant guide in `node_modules/next/dist/docs/` (resolved from this file's directory; in monorepos the `next` package may not be visible from the repo root) before writing any code. Heed deprecation notices.
+
+This block is written and re-added by `next dev` — verify at `node_modules/next/dist/server/lib/generate-agent-files.js`. Removing it from a diff only re-creates the uncommitted change; committing it with your work keeps the tree clean.
+
+<!-- END:nextjs-agent-rules -->

apps/website/CLAUDE.md

@@ -0,0 +1 @@
+@AGENTS.md

apps/website/eslint.config.mjs

@@ -0,0 +1,26 @@
+import nextCoreWebVitals from "eslint-config-next/core-web-vitals";
+
+/**
+ * Flat config — the only format `@next/eslint-plugin-next` ships as of Next 16,
+ * and what ESLint 10 will keep. Replaces the `.eslintrc.json` that
+ * `next lint` (removed in 16) used to find on its own; `pnpm lint` now runs
+ * the ESLint CLI directly.
+ *
+ * @type {import('eslint').Linter.Config[]}
+ */
+const config = [
+  { ignores: [".next/**", "out/**", "next-env.d.ts"] },
+  ...nextCoreWebVitals,
+  {
+    rules: {
+      /* New in eslint-plugin-react-hooks 7, which `eslint-config-next@16`
+         pulls in. It fires on effects that seed state from the DOM or from
+         the URL on mount -- exactly what `Nav`'s sidebar/search sync and
+         `use-mobile` do. Untangling those is a real refactor, not part of the
+         framework bump, so keep them visible as warnings for now. */
+      "react-hooks/set-state-in-effect": "warn",
+    },
+  },
+];
+
+export default config;

apps/website/package.json

@@ -8,7 +8,7 @@
     "build": "NODE_ENV=production next build",
     "build3": "pnpm run build",
     "start": "next start",
-    "lint": "next lint"
+    "lint": "eslint"
   },
   "dependencies": {
     "@example/aquarium": "workspace:*",
@@ -173,7 +173,7 @@
     "clsx": "^2.1.1",
     "lucide-react": "^1.28.0",
     "material-theme-builder": "^3.0.0",
-    "next": "15.5.22",
+    "next": "16.3.0",
     "next-themes": "^0.4.6",
     "radix-ui": "^1.6.7",
     "react": "19.2.8",
@@ -190,8 +190,8 @@
     "@types/node": "^20",
     "@types/react": "19.2.17",
     "@types/react-dom": "19.2.3",
-    "eslint": "^8.57.0",
-    "eslint-config-next": "15.5.22",
+    "eslint": "^9.39.0",
+    "eslint-config-next": "16.3.0",
     "postcss": "^8",
     "tailwindcss": "^4.3.3",
     "typescript": "^5.5.4"

apps/website/tsconfig.json

@@ -1,7 +1,11 @@
 {
   "compilerOptions": {
     "target": "ES2017",
-    "lib": ["dom", "dom.iterable", "esnext"],
+    "lib": [
+      "dom",
+      "dom.iterable",
+      "esnext"
+    ],
     "allowJs": true,
     "skipLibCheck": true,
     "strict": true,
@@ -11,17 +15,27 @@
     "moduleResolution": "bundler",
     "resolveJsonModule": true,
     "isolatedModules": true,
-    "jsx": "preserve",
+    "jsx": "react-jsx",
     "incremental": true,
     "plugins": [
       {
         "name": "next"
       }
     ],
     "paths": {
-      "@/*": ["./*"]
+      "@/*": [
+        "./*"
+      ]
     }
   },
-  "include": ["next-env.d.ts", "**/*.ts", "**/*.tsx", ".next/types/**/*.ts"],
-  "exclude": ["node_modules"]
+  "include": [
+    "next-env.d.ts",
+    "**/*.ts",
+    "**/*.tsx",
+    ".next/types/**/*.ts",
+    ".next/dev/types/**/*.ts"
+  ],
+  "exclude": [
+    "node_modules"
+  ]
 }