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/sveltekit-superforms/dist/adapters/superform.d.ts

@@ -0,0 +1,10 @@
+import type { ClientValidationAdapter } from './adapters.js';
+import type { MaybePromise } from '../utils.js';
+export type Validators<T extends Record<string, unknown>> = {
+    [P in keyof T]?: T extends any ? T[P] extends Record<string, unknown> ? Validators<T[P]> : NonNullable<T[P]> extends (infer A)[] ? A extends Record<string, unknown> ? Validators<A> : Validator<T[P]> : Validator<T[P]> : never;
+};
+export type Validator<V> = (value?: V) => MaybePromise<string | string[] | null | undefined>;
+/**
+ * @deprecated This adapter requires you to do error-prone type checking yourself. If possible, use one of the supported validation libraries instead.
+ */
+export declare const superformClient: <T extends Record<string, unknown>, T2 extends Partial<T> = Partial<T>>(schema: Validators<T2>) => ClientValidationAdapter<T>;