feat: initial scaffold for ClickTrack monorepo

Full self-hosted click track generator for cover bands.

Core technical pieces implemented:
- CTP (Click Track Protocol) TypeScript schema, Zod validator, and WAV
  renderer (44.1 kHz, 16-bit PCM, accented downbeats, ramp sections)
- MusicBrainz API client with 1 req/s rate limiting
- PostgreSQL schema (songs, tempo_maps, registry_sync_log) with triggers
- Git registry sync logic (clone/pull → validate CTP → upsert DB)
- Next.js 14 App Router: search page, track page, API routes
  (/api/songs, /api/tracks, /api/generate)
- UI components: SearchBar, SongResult, TempoMapEditor, ClickTrackPlayer
  (Web Audio API in-browser playback + WAV download)
- Docker Compose stack: app + postgres + redis + nginx + registry-sync
- Multi-stage Dockerfile with standalone Next.js output
- .env.example documenting all configuration variables
- README with setup instructions, CTP format spec, and API reference

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

docker-compose.dev.yml

@@ -0,0 +1,32 @@
+version: "3.9"
+
+# Development overrides
+# Usage: docker compose -f docker-compose.yml -f docker-compose.dev.yml up
+
+services:
+  app:
+    build:
+      target: deps   # stop before the production build step
+    command: npm run dev
+    volumes:
+      # Mount source for hot reload — node_modules stays inside the container
+      - .:/app
+      - /app/node_modules
+      - /app/.next
+    environment:
+      NODE_ENV: development
+    ports:
+      - "3000:3000"   # expose directly in dev (no nginx needed)
+
+  postgres:
+    ports:
+      - "5432:5432"   # expose for local DB tools (TablePlus, psql, etc.)
+
+  redis:
+    ports:
+      - "6379:6379"   # expose for local Redis inspection
+
+  # Disable nginx in dev
+  nginx:
+    profiles:
+      - production-only