refactor(plugin): rename detection_interval_seconds → detection_interval_minutes (#9366)

Minutes is the natural granularity for detection cadence — every
production handler already set the seconds field to a 60-multiple
(17*60, 30*60, 3600, 24*60*60). Switching to minutes drops the *60
arithmetic and matches the unit conventions used elsewhere in the
plugin worker forms.

- Proto: AdminRuntimeDefaults + AdminRuntimeConfig.detection_interval_*
  field renamed.
- Helpers: durationFromMinutes / minutesFromDuration alongside the
  existing seconds variants in plugin_scheduler.go.
- Handlers: vacuum, ec_balance, balance, erasure_coding, iceberg,
  admin_script, s3_lifecycle now declare DetectionIntervalMinutes.
- Admin: scheduler_status + types + UI templ + plugin_api.go pass
  through the new field; UI label and table cells switch to "min".

weed/admin/plugin/scheduler_status.go

@@ -47,7 +47,7 @@ type SchedulerJobTypeStatus struct {
 	Enabled                  bool       `json:"enabled"`
 	DetectionInFlight        bool       `json:"detection_in_flight"`
 	NextDetectionAt          *time.Time `json:"next_detection_at,omitempty"`
-	DetectionIntervalSeconds int32      `json:"detection_interval_seconds,omitempty"`
+	DetectionIntervalMinutes int32      `json:"detection_interval_minutes,omitempty"`
 	LastDetectedAt           *time.Time `json:"last_detected_at,omitempty"`
 	LastDetectedCount        int        `json:"last_detected_count,omitempty"`
 	LastDetectionError       string     `json:"last_detection_error,omitempty"`
@@ -347,7 +347,7 @@ func (r *Plugin) GetLaneSchedulerStatus(lane SchedulerLane) SchedulerStatus {
 			Enabled:                  state.Enabled,
 			DetectionInFlight:        state.DetectionInFlight,
 			NextDetectionAt:          state.NextDetectionAt,
-			DetectionIntervalSeconds: state.DetectionIntervalSeconds,
+			DetectionIntervalMinutes: state.DetectionIntervalMinutes,
 		}
 		if !info.lastDetectedAt.IsZero() {
 			jobStatus.LastDetectedAt = timeToPtr(info.lastDetectedAt)
@@ -430,7 +430,7 @@ func (r *Plugin) GetSchedulerStatus() SchedulerStatus {
 			Enabled:                  state.Enabled,
 			DetectionInFlight:        state.DetectionInFlight,
 			NextDetectionAt:          state.NextDetectionAt,
-			DetectionIntervalSeconds: state.DetectionIntervalSeconds,
+			DetectionIntervalMinutes: state.DetectionIntervalMinutes,
 		}
 		if !info.lastDetectedAt.IsZero() {
 			jobStatus.LastDetectedAt = timeToPtr(info.lastDetectedAt)