test(web): add middleware + i18n + messages test suites (GOO-60)

Cover frontend middleware auth/locale logic, i18n config/routing/request/navigation,
and vi/en message parity — 91 new tests across 6 files.

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

apps/web/vitest.config.ts

@@ -10,6 +10,38 @@ export default defineConfig({
     environment: 'jsdom',
     setupFiles: ['./vitest.setup.ts'],
     globals: true,
+    coverage: {
+      provider: 'v8',
+      reporter: ['text', 'text-summary', 'json-summary', 'lcov', 'clover'],
+      reportsDirectory: './coverage',
+      include: [
+        'app/**/*.ts',
+        'app/**/*.tsx',
+        'components/**/*.ts',
+        'components/**/*.tsx',
+        'lib/**/*.ts',
+        'hooks/**/*.ts',
+      ],
+      exclude: [
+        '**/*.spec.ts',
+        '**/*.spec.tsx',
+        '**/*.test.ts',
+        '**/*.test.tsx',
+        '**/__tests__/**',
+        '**/__mocks__/**',
+        '**/node_modules/**',
+        'app/**/layout.tsx',
+        'app/**/loading.tsx',
+        'app/**/error.tsx',
+        'app/**/not-found.tsx',
+      ],
+      thresholds: {
+        statements: 60,
+        branches: 50,
+        functions: 60,
+        lines: 60,
+      },
+    },
   },
   resolve: {
     alias: {