chore: record journal

.trellis/workspace/dingkang/journal-1.md

@@ -510,3 +510,24 @@ Added semantic Cesium inspection assets and controls; fixed compressed metadata
 ### Status
 
 [OK] **Completed**
+
+
+## Session 25: Cesium traffic signal countdowns
+
+**Date**: 2026-08-06
+**Task**: Cesium traffic signal countdowns
+**Branch**: `main`
+
+### Summary
+
+Added shared 7LED countdown geometry, split dynamic Cesium assets by phase group for reliable lamp-matched colors, documented the inverse-font and exporter grouping contracts, and verified the preview asset and Blender Python test suites.
+
+### Git Commits
+
+| Hash | Message |
+|------|---------|
+| `0e1574f` | (see git log) |
+
+### Status
+
+[OK] **Completed**