* feat(ui): open subagent details in chat sidebar
* chore: drop changelog edit (release generation owns it)
* refactor(ui): drop duplicate close in subagent detail panel
The sidebar region header already owns a Close Details control in both
wide and narrow layouts; the panel-local X duplicated it 40px away.
* fix(ui): stop subagent transcript loader when pane presentation retires
Pane retention wipes sidebarContent directly, so the detail slot's
render-time reset can never run again; a pending refresh timer plus
incoming task events kept refetching chat.history for a hidden panel.
* docs(ui): note close-control ownership in subagent detail header
* fix(ui): break transcript renderer import cycle
* fix(ui): use shared action cursor for subagent rows
Peter Steinberger