Fbe.delete_one silently drops other facts when an ID is duplicated

[gemshrine]

Steps to reproduce

1. Create or import two facts that share the same identifier value, and give both the property tags with values ['old', 'keep'].
2. Call Fbe.delete_one(first_fact, 'tags', 'old', fb: fb).
3. Inspect the factbase after the transaction.

Actual result

The lookup in Fbe.delete_one deletes every fact with the matching identifier, then inserts a replacement built only from the supplied fact handle. The second fact is silently lost. The sibling Fbe.delete and Fbe.overwrite helpers reject identifiers that match multiple facts, but Fbe.delete_one does not check the deletion count.

Expected result

Fbe.delete_one should detect that the identifier matched more than one fact and roll back with an error, instead of deleting unrelated facts.

Technical evidence

lib/fbe/delete_one.rb calls fbt.query("(eq #{id} #{i})").delete! and ignores the returned count before inserting a replacement. When two facts share that identifier, delete! removes both. The reconstruction copies values only from the single fact argument, so the other fact's properties are discarded.

[0crat]

@gemshrine Nice catch on that bug! 🎉 Since the team accepted it, you've bagged +18 points, just for helping us keep things solid. Found something else that doesn't look right? Don't hold back — go ahead and report it. You're sitting pretty at +7480 now, so swing by your Zerocracy account to check it out!