Cherry-picked from claude branch 7b3bec48 (fix: dedupe shared worktree ownership and title sessions immediately).
Only the worktree-dedupe half applies to main: partitionWorktreesByRegisteredProject and its callers (SessionSidebar, ElectronMiniChatApp, MobileApp, MobileSessionsSheet) plus tests and sidebar docs.
The session-title half (title sessions immediately) remains on the claude branch: the session-title runtime and its claude-code transcript translator imports do not exist on main and cannot build there until the Claude harness lands.
Serhii Dziupin
5d24d6cb2a