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/lib/__tests__/scheduledActions.test.ts

@@ -10,6 +10,8 @@ import {
   DEFAULT_SCHEDULED_ACTION_ID,
   getActionById,
   resolveTaskAction,
+  scheduleTargetDescriptor,
+  stripComposeExt,
   RISK_LABEL,
   RISK_TONE,
   RISK_BADGE_CLASSES,
@@ -18,6 +20,9 @@ import {
   type ScheduledActionCategory,
   type ScheduledActionRiskLevel,
 } from '../scheduledActions';
+import type { ScheduledTask } from '@/types/scheduling';
+
+type TargetTask = Pick<ScheduledTask, 'action' | 'target_type' | 'target_id' | 'name'>;
 
 const BACKEND_ACTIONS: BackendAction[] = [
   'restart', 'snapshot', 'prune', 'update', 'scan',
@@ -173,4 +178,46 @@ describe('scheduledActions registry', () => {
     expect(def?.riskLevel).toBe('runtime-change');
     expect(def?.helperText).toBe('Checks every stack on the selected node and updates stacks with newer images.');
   });
+
+  describe('stripComposeExt', () => {
+    it('drops a trailing .yml or .yaml and leaves other names alone', () => {
+      expect(stripComposeExt('web')).toBe('web');
+      expect(stripComposeExt('web.yml')).toBe('web');
+      expect(stripComposeExt('web.yaml')).toBe('web');
+      expect(stripComposeExt('')).toBe('');
+      expect(stripComposeExt('my.app')).toBe('my.app');
+    });
+  });
+
+  describe('scheduleTargetDescriptor', () => {
+    it('shows the stack name (without compose extension) for stack actions', () => {
+      const task: TargetTask = { action: 'restart', target_type: 'stack', target_id: 'web.yml', name: 'Nightly restart' };
+      expect(scheduleTargetDescriptor(task, 'hub')).toBe('web');
+    });
+
+    it('falls back to the task name when a stack target_id is missing', () => {
+      const task: TargetTask = { action: 'restart', target_type: 'stack', target_id: null, name: 'api.yaml' };
+      expect(scheduleTargetDescriptor(task)).toBe('api');
+    });
+
+    it('shows the node for a fleet auto-update, or a generic label without one', () => {
+      const task: TargetTask = { action: 'update', target_type: 'fleet', target_id: null, name: 'Fleet update' };
+      expect(scheduleTargetDescriptor(task, 'edge-1')).toBe('All stacks · edge-1');
+      expect(scheduleTargetDescriptor(task)).toBe('All stacks');
+    });
+
+    it('shows Entire fleet for a fleet snapshot regardless of node', () => {
+      const task: TargetTask = { action: 'snapshot', target_type: 'fleet', target_id: null, name: 'Nightly Snapshot' };
+      expect(scheduleTargetDescriptor(task, 'edge-1')).toBe('Entire fleet');
+      expect(scheduleTargetDescriptor(task)).toBe('Entire fleet');
+    });
+
+    it('shows the node for system actions (prune / scan), with a fallback', () => {
+      const scan: TargetTask = { action: 'scan', target_type: 'system', target_id: null, name: 'Vul Scan' };
+      const prune: TargetTask = { action: 'prune', target_type: 'system', target_id: null, name: 'Nightly Prune' };
+      expect(scheduleTargetDescriptor(scan, 'hub')).toBe('hub');
+      expect(scheduleTargetDescriptor(prune, 'edge-1')).toBe('edge-1');
+      expect(scheduleTargetDescriptor(scan)).toBe('Selected node');
+    });
+  });
 });