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/nodes/html-input-element/HTMLInputElementDateUtility.d.ts

@@ -0,0 +1,21 @@
+/**
+ * Date utility for HTML input elements.
+ */
+export default class HTMLInputElementDateUtility {
+    /**
+     * Returns iso week number from given date
+     *
+     * @see https://stackoverflow.com/a/6117889
+     * @param date Date or number.
+     * @returns Iso-week string.
+     */
+    static dateIsoWeek(date: Date | number): string;
+    /**
+     * Returns a date object for monday of given iso week string (\d\d\d\d-W\d\d)
+     *
+     * @param isoWeek Iso-week string.
+     * @returns Date.
+     */
+    static isoWeekDate(isoWeek: string): Date;
+}
+//# sourceMappingURL=HTMLInputElementDateUtility.d.ts.map