## What changed
Apply `tui.copy_on_select` to composer mouse selections on release, including X11 PRIMARY publication when enabled. Keep editable selections highlighted so typing can replace the selected text, even when `tui.copy_on_select_clear_selection` is enabled.
Share clipboard destination handling across the transcript, footer, and composer. Apply automatic deselection to footer selections after confirmed delivery, and release composer and footer PRIMARY ownership on focus loss or resume. Update configuration descriptions to clarify the behavior across all three surfaces.
## Testing
Add composer tests covering copy on release, retained selection highlights, replacement by typing, PRIMARY ownership lifetime, and clipboard-only status reporting for pending copies.
GitOrigin-RevId: 46999a32170149193fca561741000e97dfc458cf