v2.0.x Chore - Consider enhancing Git reference validation.

[reactive-firewall]

While the function works well, the regex pattern could be more restrictive to better match Git's reference naming rules:

References cannot begin with a dot or dash
References cannot contain consecutive dots

-	if not re.match(r'^[a-zA-Z0-9_\-./]+$', ref):
+	if not re.match(r'^[a-zA-Z0-9][a-zA-Z0-9_\-./]*$', ref) or '..' in ref:
 		raise ValueError(f"Invalid Git reference: {ref}")

[reactive-firewall]

Context is docs/utils.py

[reactive-firewall]

Note-to-self

• this is implemented, but local tests are unstable and broken (they hang rather consistently) and need to be classified as "a regression" or "work on a broken branch" . . . see PR Improved testing of git refs in documentation #291 for implementation.