feat: initial commit - Scrapyd UI web interface

- Next.js 16.0.1 + React 19.2.0 + Tailwind CSS 4.1.16
- Complete Scrapyd API integration (all 12 endpoints)
- Dashboard with real-time job monitoring
- Projects management (upload, list, delete)
- Spiders management with scheduling
- Jobs monitoring with filtering and cancellation
- System status monitoring
- Dark/light theme toggle with next-themes
- Server-side authentication via environment variables
- Docker deployment with multi-stage builds
- GitHub Actions CI/CD workflow

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

app/(dashboard)/layout.tsx

@@ -0,0 +1,19 @@
+import { Sidebar } from "@/components/sidebar";
+import { Providers } from "@/components/providers";
+
+export default function DashboardLayout({
+  children,
+}: {
+  children: React.ReactNode;
+}) {
+  return (
+    <Providers>
+      <div className="flex h-screen overflow-hidden">
+        <Sidebar />
+        <main className="flex-1 overflow-y-auto">
+          <div className="container p-6">{children}</div>
+        </main>
+      </div>
+    </Providers>
+  );
+}