Lets structured-AND IF rows compare a typed field against another
typed field, not just a constant. Authoring "Thermostat 1.Temp >
Thermostat 2.Temp" now works in-place; previously Arg2 was locked
to Constant in the editor.
- types.ts: relax isEditableStructuredAnd to permit Zone/Unit/
Thermostat/Area/TimeDate as Arg2 types (the same editable set
already accepted for Arg1).
- omni-panel-programs.ts: replace the lone constant input with
Arg2 type/object/field controls that mirror the Arg1 layout;
switching Arg2 between Constant and a reference type swaps the
sub-controls and resets defaults sensibly.
- _renderStructuredArg1Picker generalised to _renderStructuredObjectPicker
driving both sides; _defaultIxForKind extracted as a shared helper.
- Bundle rebuilt.
- dev/screenshot_arg2_object.py: targeted playwright helper that
opens the chain at slot 200 and screenshots the editor for
visual verification.