TUI: Add database progress tracking to cluster backup

- Add ProgressCallback and DatabaseProgressCallback to backup engine
- Add SetProgressCallback() and SetDatabaseProgressCallback() methods
- Wire database progress callback in backup_exec.go
- Show progress bar (Database: [████░░░] X/Y) during cluster backups
- Hide spinner when progress bar is displayed
- Use shared progress state pattern for thread-safe TUI updates

bin/README.md

@@ -4,8 +4,8 @@ This directory contains pre-compiled binaries for the DB Backup Tool across mult
 
 ## Build Information
 - **Version**: 3.42.34
-- **Build Time**: 2026-01-14_16:19:00_UTC
-- **Git Commit**: 7711a20
+- **Build Time**: 2026-01-15_14:16:33_UTC
+- **Git Commit**: eeacbfa
 
 ## Recent Updates (v1.1.0)
 - ✅ Fixed TUI progress display with line-by-line output