feat: improve Caddy import with directive detection and warnings

Add backend detection for import directives with actionable error message
Display warning banner for unsupported features (file_server, redirects)
Ensure multi-file import button always visible in upload form
Add accessibility attributes (role, aria-labelledby) to multi-site modal
Fix 12 frontend unit tests with outdated hook mock interfaces
Add data-testid attributes for E2E test reliability
Fix JSON syntax in 4 translation files (missing commas)
Create 6 diagnostic E2E tests covering import edge cases
Addresses Reddit feedback on Caddy import UX confusion

playwright.caddy-debug.config.js

@@ -0,0 +1,33 @@
+// @ts-check
+import { defineConfig, devices } from '@playwright/test';
+
+/**
+ * Standalone config for Caddy Import Debug tests
+ * Runs without security-tests dependency for faster iteration
+ */
+export default defineConfig({
+  testDir: './tests',
+  testMatch: '**/caddy-import-debug.spec.ts',
+  fullyParallel: false,
+  forbidOnly: !!process.env.CI,
+  retries: 0,
+  workers: 1,
+  reporter: [
+   ['list'],
+    ['html', { outputFolder: 'playwright-report/caddy-debug', open: 'never' }],
+  ],
+  use: {
+    baseURL: process.env.PLAYWRIGHT_BASE_URL ||'http://localhost:8080',
+    trace: 'retain-on-failure',
+    screenshot: 'only-on-failure',
+    video: 'retain-on-failure',
+    storageState: 'playwright/.auth/user.json', // Use existing auth state
+  },
+
+  projects: [
+    {
+      name: 'caddy-import-debug',
+      use: { ...devices['Desktop Chrome'] },
+    },
+  ],
+});