Fold rule: outbound rows sharing (kind, CorrelationId) become one FlowStep with
a Lifecycle list — first row's identity/time/input, latest row's outcome/
subtitle/output/error, DurationMs = sync row's own or submit→terminal wall time
(null while pending). Chain skips async steps (Notify, or first row
CachedSubmit) and links them with Async edges from the preceding chain step.
Spawner edges from a non-RouteCall are Spawn: true. The Response links from the
last non-async step of the inbound execution (the RouteCall), not the globally
last cascaded step (D9). FlowGraphView places a Response at max column + 1 so
the D9 origin does not pull it left (pulled forward from Task 7 to keep the
layout test green).
Claude-Session: https://claude.ai/code/session_01NcMG6xXdsJbmD2wYAgkK29