5.5.0 (2026-05-20) Features extract WorktreeManager interface and GitWorktreeManager class (#84) (23efb99) Documentation plan dependency-inject AgentManager's collaborators (#72) (a99374a) plan extract GitWorktreeManager class (#84) (47d9d93) retro: add retro notes for issue #76 (ceef7e0) update plan to reference #84 as prerequisite (#72) (d8ad3f5)