Preview a single If/Conditional Check leaf - the same lookup evaluate() uses internally (Variable/Expression/Time/GPIO Pin/Sun), before any comparator/Value is applied. Backs the If condition editor's "Show Current Value" button, so picking the right Value to compare against isn't guesswork.

When a "comparator" param is also supplied (the consolidated eye-preview modal's full-leaf mode), also evaluates Value the same way Value is unconditionally evaluated at runtime and applies the comparator, returning the RHS value and the boolean result too - reuses ConditionNode::PreviewLeafResult(), the exact same evaluation path a real saved leaf's evaluate() takes, so this can never drift from runtime behavior.