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/yup.d.ts

@@ -0,0 +1,5 @@
+import { type AdapterOptions, type ValidationAdapter, type Infer, type InferIn, type ClientValidationAdapter } from './adapters.js';
+import type { AnySchema, Schema } from 'yup';
+export declare function yupToJSONSchema(schema: AnySchema): import("json-schema").JSONSchema7;
+export declare const yup: <T extends Schema>(schema: T, options?: AdapterOptions<Infer<T, "yup">> | undefined) => ValidationAdapter<Infer<T, "yup">, InferIn<T, "yup">>;
+export declare const yupClient: <T extends Schema>(schema: T) => ClientValidationAdapter<Infer<T, "yup">, InferIn<T, "yup">>;