refactor(scheduler): drive scheduled-action metadata from a shared registry (#1428)

Scheduled-operation action metadata was duplicated across the backend route
validator, the DatabaseService action union, the desktop action picker, the
Timeline lanes, and the mobile labels/tones. Adding or renaming one action meant
editing all of them.

Introduce one registry per package as the single source within that package:

- backend/src/services/scheduledActionRegistry.ts owns the action list and
  target-type validation; routes/scheduledTasks.ts and DatabaseService import
  from it (BackendScheduledAction type, VALID_ACTIONS, validateActionTarget).
- frontend/src/lib/scheduledActions.ts owns the UI metadata (labels, short
  labels, categories, tones, target/node/stack/service flags, helper text) and
  drives the create-flow picker, the All Tasks label, the Timeline lanes, and
  the mobile schedule view.

Timeline lanes now group by semantic category (Lifecycle, Updates, Security,
Maintenance, Backups) sourced from the registry. The update-fleet UI alias is
made explicit via a backendAction field. Backend validation stays authoritative;
parity tests on each side keep the action sets in lockstep.

frontend/src/components/__tests__/ScheduledOperationsView.test.tsx

@@ -16,6 +16,7 @@ vi.mock('@/components/ui/toast-store', () => ({
 }));
 
 import { apiFetch, fetchForNode } from '@/lib/api';
+import { SCHEDULED_ACTIONS } from '@/lib/scheduledActions';
 import ScheduledOperationsView from '../ScheduledOperationsView';
 
 const mockedFetch = apiFetch as unknown as ReturnType<typeof vi.fn>;
@@ -169,4 +170,120 @@ describe('ScheduledOperationsView', () => {
       expect(postCall![1].localOnly).toBe(true);
     });
   });
+
+  it('renders the five registry category lanes in the timeline view', async () => {
+    render(<ScheduledOperationsView />);
+    // Timeline is the default view; the lane track always renders.
+    for (const lane of ['Lifecycle', 'Updates', 'Security', 'Maintenance', 'Backups']) {
+      expect(await screen.findByText(lane)).toBeInTheDocument();
+    }
+  });
+
+  it('offers every registry action in the create picker', async () => {
+    render(<ScheduledOperationsView />);
+
+    await userEvent.click(await screen.findByRole('button', { name: /New Schedule/ }));
+    await userEvent.click(screen.getAllByRole('combobox')[0]);
+
+    for (const action of SCHEDULED_ACTIONS) {
+      expect(await screen.findByRole('button', { name: action.label })).toBeInTheDocument();
+    }
+  });
+
+  it('shows the correct conditional fields per action', async () => {
+    render(<ScheduledOperationsView />);
+    await userEvent.click(await screen.findByRole('button', { name: /New Schedule/ }));
+
+    // The Combobox toggles selection, so each step selects an action that
+    // differs from the current one (the modal opens on the first action,
+    // Restart Stack).
+    const selectAction = async (label: string) => {
+      await userEvent.click(screen.getAllByRole('combobox')[0]);
+      await userEvent.click(await screen.findByRole('button', { name: label }));
+    };
+
+    // Default stack action (Restart Stack): Node + Stack, no Prune Targets.
+    expect(await screen.findByText('Stack')).toBeInTheDocument();
+    expect(screen.getByText('Node')).toBeInTheDocument();
+    expect(screen.queryByText('Prune Targets')).not.toBeInTheDocument();
+
+    // Node-only action: Node shown, Stack hidden.
+    await selectAction('Auto-update All Stacks');
+    expect(screen.getByText('Node')).toBeInTheDocument();
+    expect(screen.queryByText('Stack')).not.toBeInTheDocument();
+
+    // Fleet snapshot: no Node, no Stack.
+    await selectAction('Fleet Snapshot');
+    expect(screen.queryByText('Node')).not.toBeInTheDocument();
+    expect(screen.queryByText('Stack')).not.toBeInTheDocument();
+
+    // Prune: Prune Targets shown, no Node.
+    await selectAction('System Prune');
+    expect(screen.getByText('Prune Targets')).toBeInTheDocument();
+    expect(screen.queryByText('Node')).not.toBeInTheDocument();
+  });
+
+  it('emits node_id and target_id for a stack update save', async () => {
+    render(<ScheduledOperationsView />);
+
+    await userEvent.click(await screen.findByRole('button', { name: /New Schedule/ }));
+    await userEvent.type(await screen.findByPlaceholderText('e.g. Nightly stack restart'), 'stack-update');
+
+    // Switch from the default restart to the stack update action.
+    await userEvent.click(screen.getAllByRole('combobox')[0]);
+    await userEvent.click(await screen.findByRole('button', { name: 'Auto-update Stack' }));
+
+    // Node selector, then the stack selector that loads once a node is chosen.
+    await userEvent.click(screen.getAllByRole('combobox')[1]);
+    await userEvent.click(await screen.findByRole('button', { name: 'hub' }));
+    await userEvent.click(screen.getAllByRole('combobox')[2]);
+    await userEvent.click(await screen.findByRole('button', { name: 'web' }));
+
+    await userEvent.click(screen.getByRole('button', { name: 'Create' }));
+
+    await waitFor(() => {
+      const postCall = mockedFetch.mock.calls.find(
+        ([url, opts]) => url === '/scheduled-tasks' && opts?.method === 'POST',
+      );
+      expect(postCall).toBeTruthy();
+      const body = JSON.parse(postCall![1].body);
+      expect(body).toMatchObject({
+        name: 'stack-update',
+        target_type: 'stack',
+        action: 'update',
+        target_id: 'web',
+        node_id: 1,
+      });
+    });
+  });
+
+  it('maps the update-fleet alias to action=update, target_type=fleet on save', async () => {
+    render(<ScheduledOperationsView />);
+
+    await userEvent.click(await screen.findByRole('button', { name: /New Schedule/ }));
+    await userEvent.type(await screen.findByPlaceholderText('e.g. Nightly stack restart'), 'fleet-update');
+
+    await userEvent.click(screen.getAllByRole('combobox')[0]);
+    await userEvent.click(await screen.findByRole('button', { name: 'Auto-update All Stacks' }));
+
+    // Node selector is the second combobox once the node-only field renders.
+    await userEvent.click(screen.getAllByRole('combobox')[1]);
+    await userEvent.click(await screen.findByRole('button', { name: 'hub' }));
+
+    await userEvent.click(screen.getByRole('button', { name: 'Create' }));
+
+    await waitFor(() => {
+      const postCall = mockedFetch.mock.calls.find(
+        ([url, opts]) => url === '/scheduled-tasks' && opts?.method === 'POST',
+      );
+      expect(postCall).toBeTruthy();
+      const body = JSON.parse(postCall![1].body);
+      expect(body).toMatchObject({
+        name: 'fleet-update',
+        target_type: 'fleet',
+        action: 'update',
+        node_id: 1,
+      });
+    });
+  });
 });