upgrade to Next.js 16.1.6 and React 19.2

- Next.js 15.5.2 → 16.1.6, React 19.1.0 → 19.2.4
- Rename middleware.ts → proxy.ts (Next.js 16 convention)
- Remove --turbopack flags (now default in Next.js 16)
- Update eslint-config-next to v16 flat config (remove FlatCompat)
- Disable React Compiler lint rules until reactCompiler is enabled
- Update Node.js engine requirement to >=20.9.0
- Remove unused eslint-disable directives

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: prazgaitis

apps/web/components/editor/rich-text-editor.tsx

@@ -238,7 +238,6 @@ export function RichTextEditor({
         placeholder: placeholder ?? 'Write something…',
       }),
       mentionExtension,
-      // eslint-disable-next-line @typescript-eslint/no-explicit-any
     ] as any,
     content: parseEditorContent(value) ?? value ?? '',
     editable: !disabled,

apps/web/eslint.config.mjs

@@ -1,27 +1,31 @@
 // For more info, see https://github.com/storybookjs/eslint-plugin-storybook#configuration-flat-config-format
 import storybook from "eslint-plugin-storybook";
+import nextCoreWebVitals from "eslint-config-next/core-web-vitals";
 
-import { dirname } from "path";
-import { fileURLToPath } from "url";
-import { FlatCompat } from "@eslint/eslintrc";
-
-const __filename = fileURLToPath(import.meta.url);
-const __dirname = dirname(__filename);
-
-const compat = new FlatCompat({
-  baseDirectory: __dirname,
-});
-
-const eslintConfig = [...compat.extends("next/core-web-vitals", "next/typescript"), {
-  ignores: [
-    "node_modules/**",
-    ".next/**",
-    "out/**",
-    "build/**",
-    "next-env.d.ts",
-    "convex/_generated/**",
-    "storybook-static/**",
-  ],
-}, ...storybook.configs["flat/recommended"]];
+const eslintConfig = [
+  ...nextCoreWebVitals,
+  {
+    ignores: [
+      "node_modules/**",
+      ".next/**",
+      "out/**",
+      "build/**",
+      "next-env.d.ts",
+      "convex/_generated/**",
+      "storybook-static/**",
+    ],
+  },
+  {
+    rules: {
+      // Disable React Compiler rules until we enable reactCompiler in next.config
+      "react-hooks/purity": "off",
+      "react-hooks/set-state-in-effect": "off",
+      "react-hooks/static-components": "off",
+      "react-hooks/error-boundaries": "off",
+      "react-hooks/refs": "off",
+    },
+  },
+  ...storybook.configs["flat/recommended"],
+];
 
 export default eslintConfig;

apps/web/lib/rich-text.ts

@@ -137,7 +137,6 @@ export function convertContentToHtml(value: Maybe<string>): string | null {
     return generateHTML(doc, [
       StarterKit,
       createMentionExtension(),
-      // eslint-disable-next-line @typescript-eslint/no-explicit-any
     ] as any);
   }
 

apps/web/lib/server-auth.ts

@@ -57,17 +57,14 @@ export async function preloadAuthQuery<Query extends FunctionReference<"query">>
   return getBetterAuthUtils().preloadAuthQuery(query, ...args);
 }
 
-// eslint-disable-next-line @typescript-eslint/no-explicit-any
 export async function fetchAuthQuery<T>(query: any, args: Record<string, unknown>): Promise<T> {
   return getBetterAuthUtils().fetchAuthQuery(query, args);
 }
 
-// eslint-disable-next-line @typescript-eslint/no-explicit-any
 export async function fetchAuthMutation<T>(mutation: any, args: Record<string, unknown>): Promise<T> {
   return getBetterAuthUtils().fetchAuthMutation(mutation, args);
 }
 
-// eslint-disable-next-line @typescript-eslint/no-explicit-any
 export async function fetchAuthAction<T>(action: any, args: Record<string, unknown>): Promise<T> {
   return getBetterAuthUtils().fetchAuthAction(action, args);
 }

apps/web/package.json

@@ -4,8 +4,8 @@
   "private": true,
   "type": "module",
   "scripts": {
-    "dev": "PORT=3001 dotenv -e ../../.env.local -e ../../.env -- next dev --turbopack",
-    "build": "dotenv -e ../../.env.local -e ../../.env -- next build --turbopack",
+    "dev": "PORT=3001 dotenv -e ../../.env.local -e ../../.env -- next dev",
+    "build": "dotenv -e ../../.env.local -e ../../.env -- next build",
     "start": "next start",
     "typecheck": "tsc --noEmit",
     "lint": "eslint",
@@ -37,10 +37,10 @@
     "convex": "^1.28.0",
     "date-fns": "^4.1.0",
     "lucide-react": "^0.469.0",
-    "next": "15.5.2",
-    "react": "19.1.0",
+    "next": "16.1.6",
+    "react": "19.2.4",
     "react-day-picker": "^9.2.3",
-    "react-dom": "19.1.0",
+    "react-dom": "19.2.4",
     "react-markdown": "^10.1.0",
     "tailwind-merge": "^3.3.1",
     "tailwindcss-animate": "^1.0.7",
@@ -51,7 +51,6 @@
   },
   "devDependencies": {
     "@chromatic-com/storybook": "^4.1.3",
-    "@eslint/eslintrc": "^3",
     "@storybook/addon-a11y": "^10.1.10",
     "@storybook/addon-docs": "^10.1.10",
     "@storybook/addon-onboarding": "^10.1.10",
@@ -69,7 +68,7 @@
     "@vitest/coverage-v8": "^1.6.0",
     "dotenv-cli": "^10.0.0",
     "eslint": "^9",
-    "eslint-config-next": "15.5.2",
+    "eslint-config-next": "16.1.6",
     "eslint-plugin-storybook": "^10.1.10",
     "msw": "^2.3.1",
     "node-mocks-http": "^1.15.1",

apps/web/middleware.ts apps/web/proxy.tsapps/web/middleware.ts renamed to apps/web/proxy.ts

@@ -2,7 +2,7 @@ import { NextResponse } from "next/server";
 
 // Better Auth handles authentication via cookies
 // No middleware protection needed - routes are protected at the page/API level
-export default function middleware() {
+export default function proxy() {
   return NextResponse.next();
 }
 

package.json

@@ -4,7 +4,7 @@
   "license": "MIT",
   "private": true,
   "engines": {
-    "node": ">=v18.18.0"
+    "node": ">=20.9.0"
   },
   "author": {
     "url": "https://march.fit",
@@ -41,7 +41,7 @@
   "packageManager": "pnpm@10.14.0",
   "pnpm": {
     "overrides": {
-      "react-is": "19.0.0",
+      "react-is": "19.2.4",
       "require-in-the-middle": "7.5.2"
     }
   },