feat: combine process diagram and processor table into toggled card

Dashboard L3 now shows a single Processor Metrics card with
Diagram/Table toggle buttons. The diagram shows native tooltips on
hover with full processor metrics (avg, p99, invocations, error rate,
% time).

Also fixes:
- Chart x-axis uses actual timestamps instead of bucket indices
- formatDurationShort uses locale formatting with max 3 decimals

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

ui/src/utils/format-utils.ts

@@ -15,8 +15,8 @@ export function formatDurationShort(ms: number | undefined): string {
     const seconds = Math.round((ms % 60_000) / 1000);
     return seconds > 0 ? `${minutes}m ${seconds}s` : `${minutes}m`;
   }
-  if (ms >= 1000) return `${(ms / 1000).toFixed(1)}s`;
-  return `${ms}ms`;
+  if (ms >= 1000) return `${(ms / 1000).toLocaleString(undefined, { maximumFractionDigits: 1 })}s`;
+  return `${ms.toLocaleString(undefined, { maximumFractionDigits: 3 })}ms`;
 }
 
 export function statusLabel(s: string): string {