feat: full-stack frontend with gateway API integration

- Dashboard with real-time service health, screening results, stream stats
- Stock list page with search, market filter, pagination via KIS API
- Stock detail page with prices, valuation, AI analysis, catalysts
- Screening page with trigger + results display
- Pipeline monitoring with service status and stream info
- Typed API client (lib/api.ts) for all gateway endpoints
- Reusable components (Sidebar, StatCard)
- Dockerfile with build-time NEXT_PUBLIC_API_URL injection
- Docker-compatible .dockerignore

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

next.config.ts

@@ -1,7 +1,7 @@
 import type { NextConfig } from "next";
 
 const nextConfig: NextConfig = {
-  /* config options here */
+  output: "standalone",
 };
 
 export default nextConfig;