fix(metrics): adjust build duration histogram buckets for better resolution

Add lower buckets (5s, 10s) for cached builds and higher buckets (7200s, 14400s)
for cold builds up to the 4h timeout.

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

cmd/homelab-deploy/main.go

@@ -17,7 +17,7 @@ import (
 	"github.com/urfave/cli/v3"
 )
 
-const version = "0.2.3"
+const version = "0.2.4"
 
 func main() {
 	app := &cli.Command{

internal/metrics/build_metrics.go

@@ -35,7 +35,7 @@ func NewBuildCollector(reg prometheus.Registerer) *BuildCollector {
 			prometheus.HistogramOpts{
 				Name:    "homelab_deploy_build_duration_seconds",
 				Help:    "Build execution time per host",
-				Buckets: []float64{30, 60, 120, 300, 600, 900, 1200, 1800, 3600},
+				Buckets: []float64{5, 10, 30, 60, 120, 300, 600, 1800, 3600, 7200, 14400},
 			},
 			[]string{"repo", "host"},
 		),