A completed part is never revisited, so if enqueueing the re-aggregation of a touched window failed after completion, that window's published view count would permanently miss the CDN's segments. Now every window's re-aggregation is requested first; a failure releases the claim and the next pass redoes the part, which is idempotent (output keys derive from part ID + window, so the rewrite lands on the same files with the same content). Regression test covers the retry path. Assisted-by: Claude:claude-fable-5-1 Claude-Session: https://claude.ai/code/session_01GRt2L94iUkQckiL91kQkMg