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

backend/app/Http/Middleware/JwtAuth.php

@@ -0,0 +1,82 @@
+<?php
+
+namespace App\Http\Middleware;
+
+use Closure;
+use Illuminate\Http\Request;
+use Symfony\Component\HttpFoundation\Response;
+
+class JwtAuth
+{
+    public function handle(Request $request, Closure $next): Response
+    {
+        $token = $this->extractToken($request);
+
+        if (! $token) {
+            return response()->json([
+                'message' => 'Authentication required',
+            ], 401);
+        }
+
+        $payload = $this->decodeJWT($token);
+
+        if (! $payload) {
+            return response()->json([
+                'message' => 'Invalid token',
+            ], 401);
+        }
+
+        if ($payload->exp < time()) {
+            return response()->json([
+                'message' => 'Token expired',
+            ], 401);
+        }
+
+        $user = \App\Models\User::find($payload->sub);
+
+        if (! $user) {
+            return response()->json([
+                'message' => 'User not found',
+            ], 401);
+        }
+
+        auth()->setUser($user);
+        $request->setUserResolver(fn () => $user);
+
+        return $next($request);
+    }
+
+    protected function extractToken(Request $request): ?string
+    {
+        $header = $request->header('Authorization');
+
+        if (! $header || ! str_starts_with($header, 'Bearer ')) {
+            return null;
+        }
+
+        return substr($header, 7);
+    }
+
+    protected function decodeJWT(string $token): ?object
+    {
+        $parts = explode('.', $token);
+
+        if (count($parts) !== 3) {
+            return null;
+        }
+
+        list($header, $payload, $signature) = $parts;
+
+        $expectedSignature = hash_hmac('sha256', $header . '.' . $payload, config('app.key'), true);
+        $expectedSignature = base64_encode($expectedSignature);
+        $expectedSignature = str_replace(['+', '/', '='], ['-', '_', ''], $expectedSignature);
+
+        if (! hash_equals($expectedSignature, $signature)) {
+            return null;
+        }
+
+        $payload = base64_decode(str_replace(['-', '_'], ['+', '/'], $payload));
+
+        return json_decode($payload);
+    }
+}