Function rendered_layout_matches_current 

pub(crate) fn rendered_layout_matches_current(
    render_result: &FragmentRenderMap,
    all_prev_fragments: &HashMap<FragmentId, &InflightFragmentInfo>,
) -> MetaResult<bool>

Compare the rendered (preview) layout against the current in-flight layout to decide whether a reschedule is a no-op.

Dispatcher layout is intentionally not compared here. On the reschedule path it is a deterministic function of the fragment actor layout together with the stable fragment-relation metadata held in RescheduleContext, so fragment-level equality already implies dispatcher equality.

Only fragments present in render_result are compared. This is intentional: this function sits on the reschedule path, which only re-renders fragments that were loaded into the RescheduleContext. Fragment creation or deletion is handled by separate DDL / recovery paths, not by reschedule, so fragments outside the render set are irrelevant here. In other words, this is a subset check over the rendered fragments, not a full bidirectional equality check.