Add service logs feature and improve tmux popup sizing

New Features:
- Add journalctl service logs viewer via Shift+J key
- Opens tmux popup with real-time log streaming using journalctl -f
- Shows last 50 lines and follows new log entries for selected service
- Popup titled 'Logs: service.service' for clear context

Improvements:
- Increase tmux popup size to 80% width and height for better readability
- Applies to both rebuild (R) and logs (J) popups
- Compact status line text to fit new J: Logs shortcut
- Updated documentation with new key binding

Navigation Updates:
- J: Show service logs (journalctl in tmux popup)
- Status line: Tab: Host • ↑↓/jk: Select • r: Rebuild • s/S: Start/Stop • J: Logs • q: Quit

Bump version to v0.1.46

README.md

@@ -87,6 +87,7 @@ cm-dashboard • ● cmbox ● srv01 ● srv02 ● steambox
 - **↑↓ or j/k**: Navigate services
 - **s**: Start selected service (UserStart)  
 - **S**: Stop selected service (UserStop)
+- **J**: Show service logs (journalctl in tmux popup)
 - **R**: Rebuild current host
 - **q**: Quit