Fix iOS zoom and production API configuration

- Fix iOS auto-zoom on input focus (set font-size: 16px)
- Lock viewport to prevent manual zoom (maximum-scale=1.0)
- Make API URL configurable via VITE_API_URL environment variable
- Add TypeScript types for Vite environment variables
- Create deployment guide with Vercel/backend setup instructions
- Add .env.example for local development configuration
- Add vercel.json for unified frontend/backend deployment

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

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

src/services/MIDIService.ts

@@ -34,8 +34,9 @@ interface MIDISearchResponse {
 export class MIDIService {
   private baseUrl: string;
 
-  constructor(baseUrl = 'http://localhost:3001') {
-    this.baseUrl = baseUrl;
+  constructor(baseUrl?: string) {
+    // Use environment variable or fallback to localhost for development
+    this.baseUrl = baseUrl || import.meta.env.VITE_API_URL || 'http://localhost:3001';
   }
 
   async search(query: string): Promise<MIDISearchResult[]> {