Requirement

Implement the TODO at internal/metrics/metrics.go:69 to parse timer duration buckets from struct tags.

Current behavior:
When defining a Timer metric with a buckets tag, the Init function returns an error:
Field [X]: Buckets are not currently initialized for timer metrics

Context:
The TimerOptions struct already has a Buckets []time.Duration field defined in internal/metrics/factory.go:29, but the parsing logic was never implemented.

Proposed solution:

• Parse bucket strings using Go's time.ParseDuration() (supports formats like "100ms", "1.5s", "2m")
• Store parsed durations in []time.Duration
• Pass to factory.Timer(TimerOptions{...Buckets: buckets})

Example usage after implementation:
type Metrics struct {
RequestLatency metrics.Timer metric:"request_latency" buckets:"100ms,500ms,1s,5s"
}

This provides consistency with how Histogram buckets already work.