diff --git a/.trellis/workspace/dingkang/index.md b/.trellis/workspace/dingkang/index.md
index 4ecd4d8..2083ef4 100644
--- a/.trellis/workspace/dingkang/index.md
+++ b/.trellis/workspace/dingkang/index.md
@@ -8,7 +8,7 @@
 
 <!-- @@@auto:current-status -->
 - **Active File**: `journal-1.md`
-- **Total Sessions**: 17
+- **Total Sessions**: 18
 - **Last Active**: 2026-08-04
 <!-- @@@/auto:current-status -->
 
@@ -19,7 +19,7 @@
 <!-- @@@auto:active-documents -->
 | File | Lines | Status |
 |------|-------|--------|
-| `journal-1.md` | ~364 | Active |
+| `journal-1.md` | ~385 | Active |
 <!-- @@@/auto:active-documents -->
 
 ---
@@ -29,6 +29,7 @@
 <!-- @@@auto:session-history -->
 | # | Date | Title | Commits | Branch |
 |---|------|-------|---------|--------|
+| 18 | 2026-08-04 | Add OSM area preflight | `e1f5207` | `main` |
 | 17 | 2026-08-04 | Add full stage manifests | `5874cf9` | `main` |
 | 16 | 2026-08-04 | Add area quality gate | `7fcc4ee` | `main` |
 | 15 | 2026-08-04 | Add GLB stage manifests | `2832383` | `main` |
diff --git a/.trellis/workspace/dingkang/journal-1.md b/.trellis/workspace/dingkang/journal-1.md
index 56fda4e..1c45b80 100644
--- a/.trellis/workspace/dingkang/journal-1.md
+++ b/.trellis/workspace/dingkang/journal-1.md
@@ -362,3 +362,24 @@ Extended stage manifests across intermediates, reimport, blender, and preview; a
 ### Status
 
 [OK] **Completed**
+
+
+## Session 18: Add OSM area preflight
+
+**Date**: 2026-08-04
+**Task**: Add OSM area preflight
+**Branch**: `main`
+
+### Summary
+
+Added the read-only preflight:area command, a successful preflight manifest, shared OSM structural checks, and quality-gate freshness validation. OSM diagnostics now ignore action=delete historical objects; verified only nantaizi with unit fixtures, preflight, diagnose, check, and a controlled stale-manifest failure.
+
+### Git Commits
+
+| Hash | Message |
+|------|---------|
+| `e1f5207` | (see git log) |
+
+### Status
+
+[OK] **Completed**