toDataFlowSegmentView

DATA_FLOW detailed segment projection: one synthetic leaf per analyzer DataFlowSegment, with member IR labels retained as tooltip metadata. Segment member order is display metadata; it is not an IR-to-IR data-flow edge contract. Segment edges come from the inter-segment data-flow edges emitted by the loader (segmentEdgeIds non-empty); segment member IR instructions are absorbed into the segment node and never become synthetic IR-level arrows.