refactor: strengthen client boundaries and quality gates

vite.config.ts

@@ -1,4 +1,4 @@
-import { defineConfig } from 'vite';
+import { defineConfig } from 'vitest/config';
 import react from '@vitejs/plugin-react';
 import path from 'path';
 
@@ -34,4 +34,16 @@ export default defineConfig({
       },
     },
   },
+  test: {
+    environment: 'jsdom',
+    include: ['src/**/*.test.{ts,tsx}'],
+    exclude: ['api/**', 'outputs/**', 'dist/**', 'node_modules/**'],
+    setupFiles: ['./src/test/setup.ts'],
+    coverage: {
+      provider: 'v8',
+      reporter: ['text', 'json-summary'],
+      include: ['src/api/core/**/*.ts', 'src/apps/LoginPage.tsx', 'src/routes/RouteLoadBoundary.tsx'],
+      thresholds: { lines: 80, functions: 80, branches: 70, statements: 80 },
+    },
+  },
 });