chore: record journal

.trellis/workspace/dingkang/index.md

@@ -8,7 +8,7 @@
 
 <!-- @@@auto:current-status -->
 - **Active File**: `journal-1.md`
-- **Total Sessions**: 40
+- **Total Sessions**: 41
 - **Last Active**: 2026-08-24
 <!-- @@@/auto:current-status -->
 
@@ -19,7 +19,7 @@
 <!-- @@@auto:active-documents -->
 | File | Lines | Status |
 |------|-------|--------|
-| `journal-1.md` | ~866 | Active |
+| `journal-1.md` | ~887 | Active |
 <!-- @@@/auto:active-documents -->
 
 ---
@@ -29,6 +29,7 @@
 <!-- @@@auto:session-history -->
 | # | Date | Title | Commits | Branch |
 |---|------|-------|---------|--------|
+| 41 | 2026-08-24 | Use live V2X vehicle streams only | `b7031f1` | `fengshu-er-road` |
 | 40 | 2026-08-24 | Stabilize Fengshu native road compilation | `f1f829c` | `fengshu-er-road` |
 | 39 | 2026-08-18 | Complete native-only pipeline replacement | `9e0e25a` | `feature/native-road-compiler` |
 | 38 | 2026-08-18 | Complete native traffic signal workflow | `5accc0a` | `feature/native-road-compiler` |

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

@@ -864,3 +864,24 @@ Validated and committed the Fengshu Er Road native compilation fixes, including
 ### Status
 
 [OK] **Completed**
+
+
+## Session 41: Use live V2X vehicle streams only
+
+**Date**: 2026-08-24
+**Task**: Use live V2X vehicle streams only
+**Branch**: `fengshu-er-road`
+
+### Summary
+
+Replaced the Cesium preview's simulated vehicle route with authenticated OBU and target-vehicle V2X streams, converting GCJ-02 coordinates to WGS84 exactly once. Removed native traffic-simulation output, regenerated Fengshu Er Road preview, documented the no-fallback contract, and verified focused preview, V2X, budget, native-road, and signal tests.
+
+### Git Commits
+
+| Hash | Message |
+|------|---------|
+| `b7031f1` | (see git log) |
+
+### Status
+
+[OK] **Completed**