add feature branch audit file

Author: oberstet

.audit/oberstet_vendored-flatbuffers-improvements.md

@@ -0,0 +1,8 @@
+- [ ] I did **not** use any AI-assistance tools to help create this pull request.
+- [x] I **did** use AI-assistance tools to *help* create this pull request.
+- [x] I have read, understood and followed the project's AI_POLICY.md when creating code, documentation etc. for this pull request.
+
+Submitted by: @oberstet
+Date: 2025-12-11
+Related issue(s): #1810
+Branch: oberstet:vendored-flatbuffers-improvements