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/eslint.config.js

@@ -0,0 +1,23 @@
+import { dirname } from 'path';
+import { fileURLToPath } from 'url';
+
+const __dirname = dirname(fileURLToPath(import.meta.url));
+
+/** @type {import('eslint').Linter.Config[]} */
+export default [
+  {
+    ignores: ['.svelte-kit/', 'node_modules/', 'dist/', 'build/']
+  },
+  {
+    files: ['**/*.js', '**/*.ts', '**/*.svelte'],
+    languageOptions: {
+      globals: {
+        console: 'readonly',
+        document: 'readonly',
+        window: 'readonly',
+        localStorage: 'readonly',
+        fetch: 'readonly'
+      }
+    }
+  }
+];