feat: Add rate limiter with cleanup and custom error types
Rate Limiter:
- Extract rate limiting to pkg/mining/ratelimiter.go with proper lifecycle
- Add Stop() method to gracefully shutdown cleanup goroutine
- Add RateLimiter.Middleware() for Gin integration
- Add ClientCount() for monitoring
- Fix goroutine leak in previous inline implementation
Custom Errors:
- Add pkg/mining/errors.go with MiningError type
- Define error codes: MINER_NOT_FOUND, INSTALL_FAILED, TIMEOUT, etc.
- Add predefined error constructors (ErrMinerNotFound, ErrStartFailed, etc.)
- Support error chaining with WithCause, WithDetails, WithSuggestion
- Include HTTP status codes and retry policies
Service:
- Add Service.Stop() method for graceful cleanup
- Update CLI commands to use context.Background() for Manager methods
Tests:
- Add comprehensive tests for RateLimiter (token bucket, multi-IP, refill)
- Add comprehensive tests for MiningError (codes, status, retryable)
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
95ae55e4fa