feat: unify recovery, updates, and schedules under Maintenance

src/lib/maintenance.ts

@@ -0,0 +1,10 @@
+import type { WatchdogOverview } from './watchdog.js';
+import type { PlutoniumStatus } from './plutonium.js';
+
+export type MaintenancePolicy = 'health' | 'drift' | 'updates';
+export interface MaintenancePolicies { paused: boolean; health: boolean; drift: boolean; updates: boolean }
+export interface MaintenanceOverview {
+    policies: MaintenancePolicies;
+    recovery: WatchdogOverview;
+    runtime: PlutoniumStatus;
+}