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/vite.config.mts

@@ -0,0 +1,24 @@
+import { sveltekit } from '@sveltejs/kit/vite';
+import { defineConfig } from 'vite';
+import path from 'path';
+
+export default defineConfig({
+  plugins: [sveltekit()],
+  server: {
+    port: 5173,
+    host: '0.0.0.0',
+    proxy: {
+      '/api': {
+        target: 'http://backend:3000',
+        changeOrigin: true
+      }
+    }
+  },
+  test: {
+    include: ['tests/**/*.{test,spec}.{js,ts}'],
+    exclude: ['tests/e2e/**/*'],
+    globals: true,
+    environment: 'happy-dom',
+    setupFiles: ['./tests/setup.ts']
+  }
+});