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>

components/header.tsx

@@ -0,0 +1,19 @@
+interface HeaderProps {
+  title: string;
+  description?: string;
+  action?: React.ReactNode;
+}
+
+export function Header({ title, description, action }: HeaderProps) {
+  return (
+    <div className="flex items-center justify-between">
+      <div>
+        <h2 className="text-3xl font-bold tracking-tight">{title}</h2>
+        {description && (
+          <p className="text-muted-foreground">{description}</p>
+        )}
+      </div>
+      {action && <div>{action}</div>}
+    </div>
+  );
+}