- Comment shows "Enter=Save Esc=Cancel" when valid, "! value" when invalid
- Only updates on validation state change to avoid lag
- Uses deferred timer for Scintilla document sync
- Added tests for comment echo and validation error display
- replace IND_SELECTED/IND_HOVER indicators with M_HOVER(6) M_SELECTED(7) bg markers
- disable caret line highlight and native selection rendering
- re-enable sel rendering only during inline edit
- add drag-select support via nodeClicked shift signals
- use lineRangeNoEol helper to exclude EOL from indicator ranges
- add drag tracking state to editor