Add complete MIDI search and synthesis pipeline

Backend (MVP):
- Express API with /search and /fetch endpoints
- BitMidi and Dongrays search adapters with scoring heuristics
- CORS proxy with disk caching and validation
- Quality assessment and file size limits

Frontend Integration:
- Switch to @tonejs/midi parser for reliable MIDI parsing
- MIDIService for backend API communication
- MotifEngine updated to try real MIDI, fallback to synthetic
- Enhanced error handling and logging

Development:
- Concurrent frontend/backend npm scripts
- Basic project documentation

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

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

README.md

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+# MOTIF
+
+**Procedural Music Synthesis from MIDI Structure**
+
+Motif extracts structural information from existing music and re-instantiates it as original, real-time audio using the Web Audio API. Music as executable structure, not static audio.
+
+## Quick Start
+
+```bash
+# Install dependencies for both frontend and backend
+npm install
+cd server && npm install && cd ..
+
+# Run both frontend and backend
+npm run dev:all
+
+# Or run separately:
+npm run dev:backend  # Backend on :3001
+npm run dev          # Frontend on :3000
+```
+
+## Architecture
+
+- **Frontend**: TypeScript + Vite + Web Audio API
+- **Backend**: Express API for MIDI search and fetching
+- **MIDI Sources**: BitMidi, Dongrays (with synthetic fallback)
+- **Synthesis**: Pure procedural Web Audio (no samples)
+
+## How it works
+
+1. Search for MIDI by song name
+2. Extract structural features (tempo, density, roles)
+3. Map to synthesis layers (bass, drone, ostinato, texture)
+4. Generate original audio with similar "feel"
+
+## Project Structure
+
+```
+src/
+├── core/           # MotifEngine, RoleMapper
+├── synthesis/      # Web Audio synthesis engine  
+├── midi/           # MIDI parsing and processing
+├── services/       # Backend API client
+└── types/          # TypeScript interfaces
+
+server/
+├── src/
+│   ├── adapters/   # MIDI search adapters
+│   ├── services/   # Search and fetch logic
+│   └── utils/      # Scoring and validation
+└── cache/          # MIDI file cache
+```
+
+## API
+
+- `GET /api/midi/search?q=song` - Search for MIDI files
+- `GET /api/midi/fetch?u=url` - Fetch and validate MIDI
+
+Built as a technical experiment in procedural audio and Web Audio capabilities.