controller v0.240.0: seven defects from the any-tier proof and the first nightly rotation

R-486 (P1): removing an app with its backups KEPT keeps its Tier-2 record,
so the second-drive restore is no longer refused over an intact mirror.
R-484: postgis/pgvector/timescaledb images are Postgres (logical dumps).
R-485: the backup card sizes the recovery unit and the mirror(s).
R-480: a held update's sentence leaves the card once the hold is lifted.
R-477: the update's off-site lookup is one snapshots call, no stats.
R-478: a copy older than this install's deploy does not count.
R-474: "delete backups" deletes the unit, the mirror(s) and the prefs.

Tests and red-proofs per row; evidence in felhom.eu
documentation/audits/v0240-2026-09-13/ and nightly-2026-09-13-adventurelog/.

controller/internal/stacks/delete.go

@@ -598,9 +598,15 @@ func (m *Manager) RemoveStack(name string, removeHDDData bool, backupPathsToRemo
 	return resp, nil
 }
 
-// GetStackBackupData returns information about backup data for a stack.
-// drivePath is the app's home drive (HDD or system data path).
-func (m *Manager) GetStackBackupData(name string, drivePath string) (*BackupDataResponse, error) {
+// GetStackBackupData returns information about backup data for a stack — what the remove dialog
+// sizes "delete backups" from. drivePath is the app's namespace root; mirrorDirs are the app's
+// Tier-2 mirror directories (backup.Manager.Tier2MirrorDirsForApp — stacks cannot import backup).
+//
+// R-485 (v0.240.0): until v0.239.0 this read `<ns>/backups/primary/<app>/db-dumps` and a pre-v2
+// `<ns>/backups/secondary/<app>/rsync` path — both dead for an app whose backups are the recovery
+// unit and a v2 mirror — and answered `has_backups:false` over 484 MB (measured on demo-hp
+// 2026-09-13). It now sizes the whole recovery unit and every mirror.
+func (m *Manager) GetStackBackupData(name string, drivePath string, mirrorDirs []string) (*BackupDataResponse, error) {
 	_, ok := m.GetStack(name)
 	if !ok {
 		return nil, fmt.Errorf("stack %q not found", name)
@@ -617,14 +623,12 @@ func (m *Manager) GetStackBackupData(name string, drivePath string) (*BackupData
 		return resp, nil
 	}
 
-	// Check DB dump directory. drivePath is the felhom-data namespace ROOT (Model A: the in-guest
-	// drive mount itself), so backups/ sits directly under it: <nsRoot>/backups/primary/<stack>/db-dumps
-	dbDumpPath := filepath.Join(drivePath, "backups", "primary", name, "db-dumps")
-	resp.BackupPaths = append(resp.BackupPaths, buildPathInfo(dbDumpPath))
-
-	// Check cross-drive rsync directory: <nsRoot>/backups/secondary/<stack>/rsync
-	rsyncPath := filepath.Join(drivePath, "backups", "secondary", name, "rsync")
-	resp.BackupPaths = append(resp.BackupPaths, buildPathInfo(rsyncPath))
+	// The recovery unit — definition, db-dumps and volume-dumps together. drivePath is the felhom-data
+	// namespace ROOT (Model A: the in-guest drive mount itself), so backups/ sits directly under it.
+	resp.BackupPaths = append(resp.BackupPaths, buildPathInfo(appbackup.RecoveryUnitPath(drivePath, name)))
+	for _, d := range mirrorDirs {
+		resp.BackupPaths = append(resp.BackupPaths, buildPathInfo(d))
+	}
 
 	if m.isDebug() {
 		for _, p := range resp.BackupPaths {