feat: drive migration & Tier 2 restic deprecation (v0.18.0)

Phase 1: Deprecate restic as Tier 2 method (rsync only), auto-migrate on startup
Phase 2: Enhanced per-app migration with backup awareness, DB dump copy, auto-cleanup
Phase 3: Full drive migration with decommissioned state, rollback support, wizard UI
Phase 4: Hub report includes decommissioned drive state

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

controller/internal/report/builder.go

@@ -69,6 +69,15 @@ func BuildReport(
 		{Mount: "/", Label: "SSD", TotalGB: sysInfo.DiskTotalGB, UsedGB: sysInfo.DiskUsedGB, Percent: sysInfo.DiskPercent},
 	}
 	for _, sp := range storagePaths {
+		if sp.Decommissioned {
+			r.Storage = append(r.Storage, StorageReport{
+				Mount:          sp.Path,
+				Label:          sp.Label,
+				Decommissioned: true,
+				MigratedTo:     sp.MigratedTo,
+			})
+			continue
+		}
 		if sp.Disconnected {
 			r.Storage = append(r.Storage, StorageReport{
 				Mount:        sp.Path,