- Fix branch button hidden when AI is responding by decoupling
branchActionsDisabled from chatState (MessageList.tsx)
- Add sourceSessionId/sourceMessageId to SessionListItem type
(both server and desktop)
- Scan forkedFrom in listSessions to expose parent-child relationships
- Preserve sourceSessionId/sourceMessageId in branchSession optimistic store
- Add buildSessionTree utility for tree-flattened session list with
depth and isLastChild markers
- Render forked sessions indented with GitBranch icon in sidebar
- Add comprehensive tests (187 total: 81 desktop + 106 server)
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>