Initial commit: 3D Viewer application

Features:
- Vue 3 frontend with Three.js/Online3DViewer
- Node.js API with PostgreSQL and Redis
- Python worker for model conversion
- Docker Compose for deployment
- ViewCube navigation with drag rotation and 90° snap
- Cross-section, exploded view, and render settings
- Parts tree with visibility controls

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

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

.env.example

@@ -0,0 +1,55 @@
+# 3D Model Viewer - Environment Variables
+# Copy this file to .env and update values as needed
+
+# ===================
+# API Server
+# ===================
+NODE_ENV=development
+PORT=3000
+API_PREFIX=/api
+
+# ===================
+# Database (PostgreSQL)
+# ===================
+DATABASE_URL=postgresql://viewer:viewer_password@localhost:5432/viewer_db
+DATABASE_POOL_MIN=2
+DATABASE_POOL_MAX=10
+
+# ===================
+# Redis (BullMQ Queue)
+# ===================
+REDIS_URL=redis://localhost:6379
+
+# ===================
+# MinIO Object Storage
+# ===================
+MINIO_ENDPOINT=localhost
+MINIO_PORT=9000
+MINIO_ACCESS_KEY=minioadmin
+MINIO_SECRET_KEY=minioadmin
+MINIO_USE_SSL=false
+MINIO_BUCKET_RAW=raw-models
+MINIO_BUCKET_CONVERTED=converted-models
+MINIO_BUCKET_THUMBNAILS=thumbnails
+
+# ===================
+# Security
+# ===================
+CORS_ORIGINS=http://localhost:5173
+PRESIGNED_URL_EXPIRY=3600
+
+# ===================
+# Logging
+# ===================
+LOG_LEVEL=debug
+
+# ===================
+# Worker Settings
+# ===================
+WORKER_CONCURRENCY=2
+WORKER_MAX_RETRIES=3
+
+# ===================
+# Frontend (Vite)
+# ===================
+VITE_API_URL=http://localhost:3000