6.18.3 (2026-05-24) Performance Improvements reorder append-mode prompt for KV cache reuse (#180) (5f688bd) Documentation plan reorder append-mode prompt for KV cache reuse (#180) (bb0ddec) retro: add planning stage notes for issue #180 (3413158) retro: add retro notes for issue #166 (fae30ce) retro: add TDD stage notes for issue #180 (1560f2d)