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/server/index.d.ts

@@ -0,0 +1,4 @@
+export { defaults, defaultValues } from '../defaults.js';
+export { actionResult } from '../actionResult.js';
+export { superValidate, message, setMessage, setError, withFiles, removeFiles, type SuperValidated, type TaintedFields, type ValidationErrors } from '../superValidate.js';
+export type { Infer, InferIn, Schema } from '../adapters/adapters.js';

frontend/node_modules/sveltekit-superforms/dist/server/index.js

@@ -0,0 +1,5 @@
+// Backwards compatibility, everything should be imported from top-level in v2.
+// Duplicated in client/index.ts, because "server" path cannot be imported on client.
+export { defaults, defaultValues } from '../defaults.js';
+export { actionResult } from '../actionResult.js';
+export { superValidate, message, setMessage, setError, withFiles, removeFiles } from '../superValidate.js';