diff --git a/conductor/tracks/mma_core_engine_20260224/plan.md b/conductor/tracks/mma_core_engine_20260224/plan.md
index 6c4583d..8c64bbf 100644
--- a/conductor/tracks/mma_core_engine_20260224/plan.md
+++ b/conductor/tracks/mma_core_engine_20260224/plan.md
@@ -12,7 +12,7 @@
     - [x] Keep class structures, module docstrings (7a609ca)
     - [x] Preserve `@core_logic` or `# [HOT]` function bodies, hide others (7a609ca)
 
-## Phase 2: Track 2 - State Machine & Data Structures
+## Phase 2: Track 2 - State Machine & Data Structures [checkpoint: a518a30]
 - [x] Task: The Dataclasses (f9b5a50)
     - [x] Create `models.py` defining `Ticket` and `Track` (f9b5a50)
 - [x] Task: Worker Context Definition (ee71929)