chore: record journal

.trellis/workspace/dingkang/index.md

@@ -8,7 +8,7 @@
 
 <!-- @@@auto:current-status -->
 - **Active File**: `journal-1.md`
-- **Total Sessions**: 8
+- **Total Sessions**: 9
 - **Last Active**: 2026-08-03
 <!-- @@@/auto:current-status -->
 
@@ -19,7 +19,7 @@
 <!-- @@@auto:active-documents -->
 | File | Lines | Status |
 |------|-------|--------|
-| `journal-1.md` | ~175 | Active |
+| `journal-1.md` | ~196 | Active |
 <!-- @@@/auto:active-documents -->
 
 ---
@@ -29,6 +29,7 @@
 <!-- @@@auto:session-history -->
 | # | Date | Title | Commits | Branch |
 |---|------|-------|---------|--------|
+| 9 | 2026-08-03 | Improve Cesium cruise smoothness | `0d2dc22` | `main` |
 | 8 | 2026-08-03 | Clean stale tuft density comment | `f569d45` | `main` |
 | 7 | 2026-08-03 | Add feature registry dispatch | `ff18217` | `main` |
 | 6 | 2026-08-03 | Extract road assembly module | `0f3c1ee` | `main` |

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

@@ -173,3 +173,24 @@ Cleared stale D3 tuft_density_wave comment debt and updated parity guide known-d
 ### Status
 
 [OK] **Completed**
+
+
+## Session 9: Improve Cesium cruise smoothness
+
+**Date**: 2026-08-03
+**Task**: Improve Cesium cruise smoothness
+**Branch**: `main`
+
+### Summary
+
+Reduced Cesium preview cruise stutter by lowering dense scrub bush nodes in nantaizi from 707 to 266, preserving scrub ground cover, and trimming preview route/follow hot-path overhead without lowering default visual clarity. Verified nantaizi blender/cesium/preview rebuild, node --check, py_compile, 51 pure tests, and task validation.
+
+### Git Commits
+
+| Hash | Message |
+|------|---------|
+| `0d2dc22` | (see git log) |
+
+### Status
+
+[OK] **Completed**