Add document version and README entry to CLAUDE.md

CHANGELOG.md

@@ -22,6 +22,8 @@ Document versions of the individual guideline files are tracked separately in th
 - `README.md`, `docs/`, `prebuild.py` and the PyInstaller `.spec` to the template structure in `Python/TEMPLATE.md`
 - Note in `Python/TEMPLATE.md` that `AGENTS.md` and `DESIGN_DOCUMENT.md` are not part of the template
 - `README.md` to the session read list in `Claude/CLAUDE.md`, plus a missing top-level heading
+- `Document Version` marker in `Claude/CLAUDE.md`, starting at v2 — it is copied into projects like
+  `AGENTS.md` and the design documents, so it can go stale there the same way
 
 ### Changed
 - Document versions bumped for the structural changes released on 2026-08-18:

Claude/CLAUDE.md

@@ -1,5 +1,7 @@
 # CLAUDE.md
 
+**Document Version:** v2 (independent, incremented on structural changes)
+
 ## First-time setup
 
 **At the start of every new session, read all of the following files before doing anything else:**