docs: add engineering workflow rules to AGENTS.md

Author: bramp

AGENTS.md

@@ -8,3 +8,11 @@ agent. All AI-generated responses are reviewed or approved by @bramp before or
 shortly after posting.
 
 If you have concerns about an AI-generated response, please tag @bramp directly.
+
+## Engineering Workflow Rules
+
+To maintain a clean and transparent project history, the following rules MUST be followed:
+
+1. **Prefer Rebase:** Always prefer `rebase` over `merge` when updating branches or incorporating changes. Avoid "merge bubbles" in the git history.
+2. **Squash Commits:** If a pull request contains multiple commits, squash them into a single, clean change before merging to ensure a readable history.
+3. **Communicate Actions:** Always post a comment on a Pull Request when taking any action (rebasing, testing, or merging) so that contributors and maintainers are aware of the status.