fix(tui): handle tea.InterruptMsg for proper Ctrl+C cancellation

Bubbletea v1.3+ sends InterruptMsg for SIGINT signals instead of
KeyMsg with 'ctrl+c', causing cancellation to not work properly.

- Add tea.InterruptMsg handling to restore_exec.go
- Add tea.InterruptMsg handling to backup_exec.go
- Add tea.InterruptMsg handling to menu.go
- Call cleanup.KillOrphanedProcesses on all interrupt paths
- No zombie pg_dump/pg_restore/gzip processes left behind

Fixes Ctrl+C not working during cluster restore/backup operations.

v3.42.50

bin/README.md

@@ -3,9 +3,9 @@
 This directory contains pre-compiled binaries for the DB Backup Tool across multiple platforms and architectures.
 
 ## Build Information
-- **Version**: 3.42.48
-- **Build Time**: 2026-01-16_14:32:45_UTC
-- **Git Commit**: 780beaa
+- **Version**: 3.42.49
+- **Build Time**: 2026-01-16_14:37:18_UTC
+- **Git Commit**: bfe99e9
 
 ## Recent Updates (v1.1.0)
 - ✅ Fixed TUI progress display with line-by-line output