validation

A validation that only rejects self-parenting looks sufficient until a re-parent to your own descendant quietly forms a cycle in the category tree.

TL;DR: Moving A under B seemed fine but created a loop because B was already A's child. The old validation only blocked self-parenting, so the fix now walks up ancestors until it hits a root, a missing parent, or the original category. It uses the standard wrapped-error check and limits the walk to ten levels to handle legacy cycles safely.

Mass-deleting Redis keys felt right until I read the docs. Versioned keys with INCR bumps make stale chat answers unreachable instead.

TL;DR: Editing an article left the Redis-cached AI answers stale, and the author's first fix—scanning and deleting every ask: key—turned out to solve the wrong problem. SCAN is non-blocking; the real pain is tracking key families across workers forever. Versioned keys fix it: bake versions into key names, bump with INCR on edits, and let TTL clean up.

The blog's AI chat now answers 'what are you working on' from local commit history: a narrow port, a version namespace bump, and term mining.