PR watch: keep AWS account ids out of public PR text #726

The PR watch wrote the AWS account id into public PR text twice: the body of #723 (in an image provenance paragraph) and a review reply on #707. ejc3/aws is public, so neither may hold an account id, even in a provenance note.

Both are cleaned up as of 2026-10-29:

• fcvm-fleet: pin admission-enforcing host and tile images #723: the body is redacted, and its three earlier revisions are deleted from the edit history.
• The two review replies (fcvm-fleet: pin admission-enforcing host and tile images #723 and fcvm-fleet: check viewer words with Claude Haiku 5.5 on Bedrock #707) are deleted and reposted with the id replaced by "(account hidden)".

Asked of the watch:

• Before posting any PR or issue text in this repository, scan it for 12-digit AWS account ids and ARNs that embed one, and redact them. Image provenance can name the image id and the source commit without the owner account.
• Add the same check to whatever posts review replies.