feat: show node and fleet targets on schedule timeline pills (#1480)

Timeline pills and the mobile schedule list now identify what each
scheduled run acts on instead of repeating the task name. Pills stay
compact (firing time plus a category-aware target) and carry the full
detail on hover:

- Stack actions show the stack name.
- Fleet snapshots show "Entire fleet".
- Fleet auto-updates and node-scoped prune/scan show the selected node.
- The hover tooltip adds the action label, task name, and node.

The mobile list resolves node names too, so prune and scan rows name the
node rather than the literal "system". A shared scheduleTargetDescriptor
helper removes the target-label logic that was duplicated across the
desktop and mobile views. The lifecycle lane is renamed "Stack lifecycle"
to match the action-picker category wording.

frontend/src/components/ScheduledOperationsView.tsx

@@ -21,6 +21,7 @@ import {
   SCHEDULED_ACTION_CATEGORIES,
   getActionById,
   resolveTaskAction,
+  scheduleTargetDescriptor,
   DEFAULT_SCHEDULED_ACTION_ID,
   RISK_BADGE_CLASSES,
   RISK_DOT_CLASSES,
@@ -347,6 +348,7 @@ export default function ScheduledOperationsView({ filterNodeId, onClearFilter, p
   const cronDescription = getCronDescription(formCron);
   const cronFieldError = getCronFieldError(formCron);
   const nodeOptions = useMemo(() => nodes.map(n => ({ value: String(n.id), label: n.name })), [nodes]);
+  const nodeNameById = useMemo(() => new Map(nodes.map(n => [n.id, n.name])), [nodes]);
   const actionOptions = useMemo(
     () =>
       SCHEDULED_ACTIONS.map(o => ({
@@ -498,9 +500,11 @@ export default function ScheduledOperationsView({ filterNodeId, onClearFilter, p
                             {lanePills.map((pill, idx) => {
                               const leftPct = ((pill.runAt - now) / TIMELINE_WINDOW_MS) * 100;
                               const clamped = Math.max(0, Math.min(100, leftPct));
-                              const targetLabel = pill.task.target_type === 'stack'
-                                ? pill.task.target_id ?? pill.task.name
-                                : pill.task.name;
+                              const nodeName = pill.task.node_id != null ? nodeNameById.get(pill.task.node_id) : undefined;
+                              const targetLabel = scheduleTargetDescriptor(pill.task, nodeName);
+                              const actionLabel = resolveTaskAction(pill.task)?.label ?? pill.task.action;
+                              const tooltip = `${actionLabel} · ${pill.task.name} · ${formatHourTick(pill.runAt)}`
+                                + (nodeName ? ` · ${nodeName}` : '');
                               return (
                                 <button
                                   key={`${pill.task.id}-${idx}-${pill.runAt}`}
@@ -516,7 +520,7 @@ export default function ScheduledOperationsView({ filterNodeId, onClearFilter, p
                                       ? 'translate(-100%, -50%)'
                                       : 'translate(0, -50%)',
                                   }}
-                                  title={`${pill.task.name} · ${formatHourTick(pill.runAt)} · ${targetLabel}`}
+                                  title={tooltip}
                                 >
                                   <span>{formatHourTick(pill.runAt)}</span>
                                   <span className="opacity-70 max-w-[100px] truncate">{targetLabel}</span>