Completes the duplicated-chrome class fix:
- Focus-in (CSI I) now routes through the same rate-limited full-redraw
recovery as Ctrl+L//redraw, clearing ghost prompt/composer copies after
Alt+Tab / tab switches (focus-regain variant reported on #60920, #25337)
- Document display.cli_rebuild_scrollback_on_redraw in configuration.md
- Register the new default in hermes_cli/config_defaults.py (moved from
the pre-refactor config.py location the salvaged commit targeted)
3bd98ec4bf