v3.42.35: Standardize TUI title prefixes for consistency

- [CHECK] for diagnosis, previews, validations
- [STATS] for status, history, metrics views
- [SELECT] for selection/browsing screens
- [EXEC] for execution screens (backup/restore)
- [CONFIG] for settings/configuration

Fixed 8 files with inconsistent prefixes:
- diagnose_view.go: [SEARCH] → [CHECK]
- settings.go: [CFG] → [CONFIG]
- menu.go: [DB] → clean title
- history.go: [HISTORY] → [STATS]
- backup_manager.go: [DB] → [SELECT]
- archive_browser.go: [PKG]/[SEARCH] → [SELECT]
- restore_preview.go: added [CHECK]
- restore_exec.go: [RESTORE] → [EXEC]

internal/tui/restore_exec.go

@@ -321,9 +321,9 @@ func (m RestoreExecutionModel) View() string {
 	s.Grow(512) // Pre-allocate estimated capacity for better performance
 
 	// Title
-	title := "[RESTORE] Restoring Database"
+	title := "[EXEC] Restoring Database"
 	if m.restoreType == "restore-cluster" {
-		title = "[RESTORE] Restoring Cluster"
+		title = "[EXEC] Restoring Cluster"
 	}
 	s.WriteString(titleStyle.Render(title))
 	s.WriteString("\n\n")