* feat: add workspace rename dialog
- Adds a modal dialog to rename the current workspace
- Supports both Niri (via IPC socket) and Hyprland (via hyprctl dispatch)
- Default keybinding: Ctrl+Shift+R to open the dialog
- Pre-fills with current workspace name
- Allows setting empty name to reset to default
* refactor: wrap WorkspaceRenameModal in LazyLoader
Reduces memory footprint when the modal is not in use.
