feat(status): 24-hour activity sparklines on worker pulse cards

Each worker card on /status now renders a stacked-bar histogram of the
last 24 hourly buckets — successes from the bottom up in primary blue,
failures from the top down in destructive red, idle hours as a thin
baseline.  Heights normalise to the loudest hour in the series so quiet
workers still show shape.

- /api/status/workers: extended the response with activity24h per
  worker, computed via a generate_series CTE joined to analyzer_jobs /
  rmm_executions / sync_history (zero-fill so the 24-bucket shape is
  consistent regardless of activity).
- ActivitySparkline (components/status/activity-sparkline.tsx) — pure
  flex-end bar strip, no recharts dependency, 32px tall by default.
- WorkerPulse renders the strip below the in-flight / 1h tiles with
  "24h ago" / "now" labels.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

components/status/activity-sparkline.tsx

@@ -0,0 +1,91 @@
+/* ActivitySparkline — 24-bucket success/failure strip for a worker.
+ *
+ * Each column is one hour of activity.  Successes stack from the top
+ * down in brand blue; failures stack from the top down in destructive
+ * red over the success column so the worst hours read first.  Heights
+ * scale to the loudest hour in the series so a quiet worker still
+ * shows shape.
+ *
+ * No tooltip — hover-title gives the count.  At 24px tall this is a
+ * stacked bar histogram, not a line chart, so absolute counts read
+ * directly. */
+
+'use client';
+
+import { cn } from '@/lib/utils';
+
+interface ActivityBucket {
+  hour: string;
+  success: number;
+  failure: number;
+}
+
+interface ActivitySparklineProps {
+  data: ActivityBucket[];
+  className?: string;
+  height?: number;
+}
+
+function fmtHour(iso: string): string {
+  return new Date(iso).toLocaleTimeString(undefined, {
+    hour: 'numeric',
+    minute: '2-digit',
+  });
+}
+
+export function ActivitySparkline({
+  data,
+  className,
+  height = 32,
+}: ActivitySparklineProps) {
+  if (data.length === 0) {
+    return null;
+  }
+
+  const max = Math.max(1, ...data.map((d) => d.success + d.failure));
+
+  return (
+    <div className={cn('flex items-end gap-px w-full', className)} style={{ height }}>
+      {data.map((bucket, i) => {
+        const total = bucket.success + bucket.failure;
+        const totalPct = (total / max) * 100;
+        const failPct = total > 0 ? (bucket.failure / total) * 100 : 0;
+        const succPct = 100 - failPct;
+        const empty = total === 0;
+        return (
+          <span
+            key={bucket.hour}
+            title={
+              empty
+                ? `${fmtHour(bucket.hour)} · idle`
+                : `${fmtHour(bucket.hour)} · ${bucket.success} ok · ${bucket.failure} fail`
+            }
+            aria-label={`${fmtHour(bucket.hour)}: ${bucket.success} ok, ${bucket.failure} fail`}
+            className="relative flex-1 min-w-[1px] flex flex-col-reverse rounded-[1px] overflow-hidden"
+            style={{ height: `${empty ? 12 : Math.max(totalPct, 8)}%` }}
+            data-bucket-index={i}
+          >
+            {/* Success segment (bottom) */}
+            {bucket.success > 0 && (
+              <span
+                className="bg-primary/70"
+                style={{ height: `${succPct}%` }}
+              />
+            )}
+            {/* Failure segment (top) */}
+            {bucket.failure > 0 && (
+              <span
+                className="bg-destructive"
+                style={{ height: `${failPct}%` }}
+              />
+            )}
+            {/* Idle hour — render a thin baseline */}
+            {empty && (
+              <span className="bg-border/60 h-px self-end w-full" />
+            )}
+          </span>
+        );
+      })}
+    </div>
+  );
+}

components/status/worker-pulse.tsx

@@ -15,12 +15,20 @@
 
 import { Card, CardContent } from '@/components/ui/card';
 import { StatusLight, type StatusLightState } from '@/components/ui/status-light';
+import { ActivitySparkline } from '@/components/status/activity-sparkline';
+
+interface ActivityBucket {
+  hour: string;
+  success: number;
+  failure: number;
+}
 
 interface WorkerSnapshot {
   name: string;
   lastActivity: string | null;
   inFlight: number;
   oneHour: { success: number; failure: number };
+  activity24h?: ActivityBucket[];
 }
 
 interface WorkerPulseProps {
@@ -84,6 +92,16 @@ export function WorkerPulse({ worker, freshnessMinutes = 30 }: WorkerPulseProps)
           <Stat label="Fail · 1h" value={oneHour.failure} tone={oneHour.failure > 0 ? 'error' : 'default'} />
         </div>
 
+        {worker.activity24h && worker.activity24h.length > 0 && (
+          <div className="space-y-1">
+            <ActivitySparkline data={worker.activity24h} />
+            <div className="flex justify-between text-[10px] text-muted-foreground num">
+              <span>24h ago</span>
+              <span>now</span>
+            </div>
+          </div>
+        )}
+
         <p className="text-xs text-muted-foreground">
           Last activity <span className="num">{relTime(lastActivity)}</span>
         </p>