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-details-element/HTMLDetailsElement.d.ts

@@ -0,0 +1,36 @@
+import Event from '../../event/Event.js';
+import HTMLElement from '../html-element/HTMLElement.js';
+import * as PropertySymbol from '../../PropertySymbol.js';
+import Attr from '../attr/Attr.js';
+/**
+ * HTMLDetailsElement
+ *
+ * @see https://developer.mozilla.org/en-US/docs/Web/API/HTMLDetailsElement
+ */
+export default class HTMLDetailsElement extends HTMLElement {
+    get ontoggle(): ((event: Event) => void) | null;
+    set ontoggle(value: ((event: Event) => void) | null);
+    /**
+     * Returns the open attribute.
+     */
+    get open(): boolean;
+    /**
+     * Sets the open attribute.
+     *
+     * @param open New value.
+     */
+    set open(open: boolean);
+    /**
+     * @override
+     */
+    [PropertySymbol.onSetAttribute](attribute: Attr, replacedAttribute: Attr | null): void;
+    /**
+     * @override
+     */
+    [PropertySymbol.onRemoveAttribute](removedAttribute: Attr): void;
+    /**
+     * @override
+     */
+    dispatchEvent(event: Event): boolean;
+}
+//# sourceMappingURL=HTMLDetailsElement.d.ts.map