Improve operational UX, recovery flows, and action safety

Implement the approved UX review across Fleet, Betas, Library, deployments, and Settings. Add reviewed promotion and reconciliation plans, atomic queued-removal cancellation, recoverable beta drafts and launch inputs, accessible controls, and mobile improvements.

Validated with 473 tests, a clean typecheck, production build, and isolated desktop/mobile browser walkthroughs. Include the review and implementation coverage notes.

src/lib/system-status.ts

@@ -0,0 +1,15 @@
+export interface SetupCheck {
+    id: string;
+    title: string;
+    state: 'ready' | 'attention' | 'unconfigured' | 'unverified';
+    detail: string;
+    href?: string;
+    action?: string;
+}
+export interface SystemStatus {
+    checkedAt: string;
+    checks: SetupCheck[];
+    readyServers: number;
+    totalServers: number;
+    savedKeys: number;
+}