chore: upgrade to Next.js 16

eslint.config.mjs

@@ -0,0 +1,78 @@
+import nextTypescript from 'eslint-config-next/typescript'
+import nextCoreWebVitals from 'eslint-config-next/core-web-vitals'
+import { dirname } from 'path'
+import { fileURLToPath } from 'url'
+import js from '@eslint/js'
+import tsPlugin from '@typescript-eslint/eslint-plugin'
+import tsParser from '@typescript-eslint/parser'
+
+const __filename = fileURLToPath(import.meta.url)
+const __dirname = dirname(__filename)
+
+export default [
+  ...nextTypescript,
+  js.configs.recommended,
+  ...nextCoreWebVitals,
+  {
+    files: ['src/**/*.{ts,tsx}'],
+    languageOptions: {
+      parser: tsParser,
+      parserOptions: {
+        project: './tsconfig.json',
+      },
+      globals: {
+        React: 'readonly',
+      },
+    },
+    plugins: {
+      '@typescript-eslint': tsPlugin,
+    },
+    rules: {
+      ...tsPlugin.configs['recommended'].rules,
+      '@typescript-eslint/no-misused-promises': 'off',
+      '@typescript-eslint/no-unused-vars': [
+        'error',
+        { argsIgnorePattern: '^_', varsIgnorePattern: '^_' },
+      ],
+      // TypeScript handles redeclaration checks - allows type + value with same name
+      'no-redeclare': 'off',
+      // TODO: Refactor hooks to use React Query instead of useEffect + setState pattern
+      'react-hooks/set-state-in-effect': 'off',
+    },
+  },
+  {
+    // TypeScript declaration files - disable no-undef as types are ambient
+    files: ['src/**/*.d.ts'],
+    rules: {
+      'no-undef': 'off',
+    },
+  },
+  {
+    // TODO: add linting for tests
+    // Test files - lint without type-checking (not in tsconfig.json project)
+    // TODO: add type checking for tests
+    // files: ['test/**/*.{ts,tsx}'],
+    // languageOptions: {
+    //   parser: tsParser,
+    //   globals: jestPlugin.environments.globals.globals,
+    // },
+    // plugins: {
+    //   '@typescript-eslint': tsPlugin,
+    //   jest: jestPlugin,
+    // },
+    // rules: {
+    //   ...tsPlugin.configs['recommended'].rules,
+    //   ...jestPlugin.configs['recommended'].rules,
+    //   '@typescript-eslint/no-unused-vars': [
+    //     'error',
+    //     { argsIgnorePattern: '^_', varsIgnorePattern: '^_' },
+    //   ],
+    //   // TODO: clean up conditional tests
+    //   'jest/no-conditional-expect': 'off',
+    // },
+  },
+  {
+    // TODO: lint tests
+    ignores: ['node_modules/', '.next/', 'build/', 'test/', '*.mjs', '*.js'],
+  },
+]