- Add FORM_EDIT input mode for editing text fields
- Add actions: NEXT_FIELD, PREV_FIELD, EDIT_TEXT, ACTIVATE_FIELD
- Support 'i' key to focus first form field
- Tab/Shift+Tab to navigate between fields
- Enter on text input fields to edit them
- Real-time text editing with live preview
- Enter/Esc to exit edit mode
- Checkbox toggle support (press Enter on checkbox)
- Status bar shows "-- INSERT --" mode and current text
- Form fields highlighted when active
Keyboard shortcuts:
- i: Focus first form field
- Tab: Next field
- Shift+Tab: Previous field
- Enter: Activate/edit field or toggle checkbox
- Esc: Exit edit mode
