When switching themes, ratatui's incremental diff engine may miss
color-only changes in sidebar cells that were rendered with
theme-resolved UiTheme fields rather than palette constants routed
through the backend remap layer. This manifests as the sidebar
retaining the previous theme's colors until a window resize or
conversation turn triggers a full repaint.
Add a force_next_full_repaint flag on App that is set whenever a
theme or background_color ConfigUpdated event is processed. The
main render loop merges this into the existing force_terminal_repaint
mechanism, which clears the terminal and redraws every cell.
Hu Qiantao
b1cc344d21