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/drift-plan.ts

@@ -0,0 +1,26 @@
+export interface DriftPlanFile {
+    server: string;
+    relPath: string;
+    kind: string;
+    driftKind: 'untracked' | 'missing' | 'replace';
+    beforeSha256: string | null;
+    afterSha256: string | null;
+    beforeSize: number | null;
+    afterSize: number | null;
+}
+
+export interface DriftPlan {
+    fingerprint: string;
+    scannedAt: string;
+    servers: string[];
+    files: DriftPlanFile[];
+}
+
+export interface DriftResult {
+    deploymentId: string | null;
+    perServer: { server: string; removed: string[]; restored: string[]; skipped: string[] }[];
+    totalRemoved: number;
+    totalRestored: number;
+    totalServers: number;
+    dryRun: boolean;
+}