Clarify PR title naming guidance

Author: cristianrgreco

AGENTS.md

@@ -51,7 +51,7 @@ It captures practical rules that prevent avoidable CI and PR churn.
    - Never bypass signing (for example, do not use `--no-gpg-sign`).
    - If signing fails (for example, passphrase/key issues), stop and ask the user to resolve signing, then retry.
 8. Push branch. Ask for explicit user permission before any force push.
-9. Open PR against `main` using a human-readable title (no `feat(...)` / `fix(...)` prefixes).
+9. Open PR against `main` using a human-readable title (no `feat(...)` / `fix(...)` prefixes, and no agent-identifying prefixes or suffixes).
    - When using `gh` to create/edit PR descriptions, prefer `--body-file <path>` over inline `--body`.
    - This avoids shell command substitution issues when the body contains backticks.
 10. Add labels for both change type and semantic version impact.