Remove stats from .runtime/*.json observable state (gt-lfi2d)

Remove Stats fields from witness and refinery types that tracked
observable metrics (total counts, today counts). These are now
handled by the activity stream/beads system instead.

Removed:
- WitnessStats type and Stats field from Witness
- RefineryStats type and Stats field from Refinery
- LastCheckAt field from Witness
- Stats display from gt witness status
- Stats display from gt refinery status
- Stats increment code from refinery.completeMR()

Kept minimal process state:
- RigName, State, PID, StartedAt (both)
- MonitoredPolecats, Config, SpawnedIssues (witness)
- CurrentMR, PendingMRs, LastMergeAt (refinery)

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

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

internal/cmd/refinery.go

@@ -277,12 +277,6 @@ func runRefineryStatus(cmd *cobra.Command, args []string) error {
 		fmt.Printf("  Last merge: %s\n", ref.LastMergeAt.Format("2006-01-02 15:04:05"))
 	}
 
-	fmt.Printf("\n  %s\n", style.Bold.Render("Statistics:"))
-	fmt.Printf("    Merged today:  %d\n", ref.Stats.TodayMerged)
-	fmt.Printf("    Failed today:  %d\n", ref.Stats.TodayFailed)
-	fmt.Printf("    Total merged:  %d\n", ref.Stats.TotalMerged)
-	fmt.Printf("    Total failed:  %d\n", ref.Stats.TotalFailed)
-
 	return nil
 }
 

internal/cmd/witness.go

@@ -259,10 +259,6 @@ func runWitnessStatus(cmd *cobra.Command, args []string) error {
 		fmt.Printf("  Started: %s\n", w.StartedAt.Format("2006-01-02 15:04:05"))
 	}
 
-	if w.LastCheckAt != nil {
-		fmt.Printf("  Last check: %s\n", w.LastCheckAt.Format("2006-01-02 15:04:05"))
-	}
-
 	// Show monitored polecats
 	fmt.Printf("\n  %s\n", style.Bold.Render("Monitored Polecats:"))
 	if len(w.MonitoredPolecats) == 0 {
@@ -273,13 +269,6 @@ func runWitnessStatus(cmd *cobra.Command, args []string) error {
 		}
 	}
 
-	fmt.Printf("\n  %s\n", style.Bold.Render("Statistics:"))
-	fmt.Printf("    Checks today:      %d\n", w.Stats.TodayChecks)
-	fmt.Printf("    Nudges today:      %d\n", w.Stats.TodayNudges)
-	fmt.Printf("    Total checks:      %d\n", w.Stats.TotalChecks)
-	fmt.Printf("    Total nudges:      %d\n", w.Stats.TotalNudges)
-	fmt.Printf("    Total escalations: %d\n", w.Stats.TotalEscalations)
-
 	return nil
 }