feat: Reinitialize frontend with SvelteKit and TypeScript

- Delete old Vite+Svelte frontend
- Initialize new SvelteKit project with TypeScript
- Configure Tailwind CSS v4 + DaisyUI
- Implement JWT authentication with auto-refresh
- Create login page with form validation (Zod)
- Add protected route guards
- Update Docker configuration for single-stage build
- Add E2E tests with Playwright (6/11 passing)
- Fix Svelte 5 reactivity with $state() runes

Known issues:
- 5 E2E tests failing (timing/async issues)
- Token refresh implementation needs debugging
- Validation error display timing

frontend/node_modules/happy-dom/lib/browser/utilities/BrowserFrameValidator.d.ts

@@ -0,0 +1,23 @@
+import IBrowserFrame from '../types/IBrowserFrame.js';
+import { URL } from 'url';
+/**
+ * Browser frame validator.
+ */
+export default class BrowserFrameValidator {
+    /**
+     * Returns true if the frame navigation complies with the cross origin policy.
+     *
+     * @param frame Frame.
+     * @param toURL URL.
+     * @returns True if the frame navigation complies with the cross origin policy.
+     */
+    static validateCrossOriginPolicy(frame: IBrowserFrame, toURL: URL): boolean;
+    /**
+     * Returns true if navigation is allowed for the frame.
+     *
+     * @param frame Frame.
+     * @returns True if navigation is allowed for the frame.
+     */
+    static validateFrameNavigation(frame: IBrowserFrame): boolean;
+}
+//# sourceMappingURL=BrowserFrameValidator.d.ts.map