test: add comprehensive API tests for backend and frontend

Backend:
- Add API test files for auth, program, downloader, config, log, bangumi extended, search, and passkey endpoints
- Update conftest.py with new fixtures (app, authed_client, unauthed_client, mock_program, mock_webauthn, mock_download_client)
- Update factories.py with make_config and make_passkey functions

Frontend:
- Setup vitest testing infrastructure with happy-dom environment
- Add test setup file with mocks for axios, router, i18n, localStorage
- Add mock API data for testing
- Add tests for API logic, store logic, hooks, and basic components
- Add @vue/test-utils and happy-dom dev dependencies

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

webui/vitest.config.ts

@@ -0,0 +1,38 @@
+import { resolve } from 'node:path';
+import { defineConfig } from 'vitest/config';
+import vue from '@vitejs/plugin-vue';
+import AutoImport from 'unplugin-auto-import/vite';
+
+export default defineConfig({
+  plugins: [
+    vue(),
+    AutoImport({
+      imports: ['vue', 'vitest', 'pinia'],
+      dts: false,
+    }),
+  ],
+  test: {
+    environment: 'happy-dom',
+    globals: true,
+    setupFiles: ['./src/test/setup.ts'],
+    include: ['src/**/*.{test,spec}.{js,ts}'],
+    coverage: {
+      provider: 'v8',
+      reporter: ['text', 'json', 'html'],
+      include: ['src/**/*.{ts,vue}'],
+      exclude: [
+        'src/test/**',
+        'src/**/*.d.ts',
+        'src/main.ts',
+        'src/router/**',
+      ],
+    },
+  },
+  resolve: {
+    alias: {
+      '~': resolve(__dirname, './'),
+      '@': resolve(__dirname, 'src'),
+      '#': resolve(__dirname, 'types'),
+    },
+  },
+});