feat: Single-port deployment with improved error handling and SvelteKit static build

- Frontend now uses @sveltejs/adapter-static for production builds
- Backend serves both API and static files from single port (originally port 3000)
- Removed all throw statements from services to avoid Elysia prototype errors
- Fixed favicon serving and SvelteKit assets path handling
- Added ecosystem.config.js for PM2 process management
- Comprehensive deployment documentation (PM2 + HAProxy)
- Updated README with single-port architecture
- Created start.sh script for easy production start

start.sh

@@ -0,0 +1,5 @@
+#!/bin/bash
+# Production start script
+# Run backend server (Elysia errors are harmless warnings that don't affect functionality)
+
+exec bun src/backend/index.js