chore: record journal

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

@@ -26,3 +26,24 @@ Initialized Trellis project scaffolding and replaced the incorrect frontend spec
 ### Status
 
 [OK] **Completed**
+
+
+## Session 2: Refactor Cesium material export contract
+
+**Date**: 2026-08-03
+**Task**: Refactor Cesium material export contract
+**Branch**: `main`
+
+### Summary
+
+Moved Cesium material export overrides into catalog-backed material contracts saved as Blender material custom properties. Kept legacy name-table fallback for old .blend files, updated Blender/spec guidance, and verified with unit tests, py_compile, diff check, and parity before/after comparison showing only expected cesium_export blend property diffs.
+
+### Git Commits
+
+| Hash | Message |
+|------|---------|
+| `0635c09` | (see git log) |
+
+### Status
+
+[OK] **Completed**