diff --git a/conductor/tracks/mma_core_engine_20260224/plan.md b/conductor/tracks/mma_core_engine_20260224/plan.md
index 6117de1..e09a0af 100644
--- a/conductor/tracks/mma_core_engine_20260224/plan.md
+++ b/conductor/tracks/mma_core_engine_20260224/plan.md
@@ -29,7 +29,7 @@
     - [x] Before executing `write_file`/`shell_runner.py` tools in step-mode, prompt user for confirmation (1afd9c8)
     - [x] Provide functionality to mutate the history JSON before resuming execution (1afd9c8)
 
-## Phase 4: Track 4 - Tier 4 QA Interception
+## Phase 4: Track 4 - Tier 4 QA Interception [checkpoint: 61d17ad]
 - [x] Task: The Interceptor Loop (bc654c2)
     - [x] Catch `subprocess.run()` execution errors inside `shell_runner.py` (bc654c2)
 - [x] Task: Tier 4 Instantiation (8e4e326)