Add Factorio World Management feature to GSM

- Add gsm-frontend to repository (React + Vite + TailwindCSS)
- New "Worlds" tab for Factorio server with:
  - List saved worlds with Start/Delete actions
  - Create new world with full map generation parameters
  - Preset selection (Default, Rich Resources, Rail World, etc.)
  - Save custom configurations as templates
- Show which save will be loaded in Overview tab
- Lock world management while server is running
- Backend changes deployed to server separately

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

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

gsm-frontend/vite.config.js

@@ -0,0 +1,11 @@
+import { defineConfig } from 'vite'
+import react from '@vitejs/plugin-react'
+
+export default defineConfig({
+  plugins: [react()],
+  server: {
+    proxy: {
+      '/api': 'http://localhost:3000'
+    }
+  }
+})