Initial implementation of NetWatch network latency monitor

SPA for real-time latency monitoring to 10 internet hosts:
- 250ms update interval with 300s history sparkline graphs
- Color-coded latency display (green <50ms to red >500ms)
- HEAD request timing with no-cors mode for cross-origin support
- Built with Vite + Tailwind CSS v4, all dependencies bundled
- Designed for static bucket deployment

.gitignore

@@ -0,0 +1,4 @@
+node_modules/
+dist/
+.DS_Store
+*.log