fix: upgrade to Next.js 16 and fix pnpm 10 compatibility

- Upgrade Next.js from 15.5.6 to 16.1.1
- Upgrade eslint-config-next to 16.1.1 for ESLint 9 flat config support
- Add required ESLint dependencies (@eslint/js, @eslint/eslintrc, typescript-eslint)
- Rewrite eslint.config.mjs to use Next.js 16's native flat config
- Fix React hooks lint errors (set-state-in-effect) by using queueMicrotask
- Fix exhaustive-deps warning in LookupInput
- Suppress false positive refs lint error in react-hook-form integration

This resolves pnpm 10's stricter package resolution and module exports handling.

package.json

@@ -25,7 +25,7 @@
 		"clsx": "^2.1.1",
 		"date-fns": "^4.1.0",
 		"date-fns-tz": "^3.2.0",
-		"next": "^15.5.6",
+		"next": "^16.1.1",
 		"next-themes": "^0.4.6",
 		"overlayscrollbars": "^2.12.0",
 		"overlayscrollbars-react": "^0.5.6",
@@ -44,6 +44,8 @@
 		"@codecov/vite-plugin": "^1.9.1",
 		"@commitlint/cli": "^20.0.0",
 		"@commitlint/config-conventional": "^20.0.0",
+		"@eslint/eslintrc": "^3.3.3",
+		"@eslint/js": "^9.39.2",
 		"@posthog/nextjs-config": "^1.3.6",
 		"@tailwindcss/postcss": "^4.1.15",
 		"@testing-library/jest-dom": "^6.9.1",
@@ -55,8 +57,8 @@
 		"@typescript-eslint/parser": "^8.46.2",
 		"@vitest/coverage-v8": "^4.0.1",
 		"@vitest/ui": "^4.0.1",
-		"eslint": "^9.38.0",
-		"eslint-config-next": "15.5.6",
+		"eslint": "^9.39.2",
+		"eslint-config-next": "16.1.1",
 		"happy-dom": "^20.0.8",
 		"husky": "^9.0.0",
 		"lint-staged": "^16.0.0",
@@ -65,6 +67,7 @@
 		"prettier-plugin-tailwindcss": "^0.7.1",
 		"tailwindcss": "^4.1.15",
 		"typescript": "^5.9.3",
+		"typescript-eslint": "^8.50.1",
 		"vitest": "^4.0.1"
 	},
 	"ct3aMetadata": {