v3.9.27

feat(marker): bitfun-loopx co-author trailer on every agent commit

Commits inside console-managed clones now carry the bitfun-loopx trailer, countable via GitHub commit search. Two layers: a commit-msg hook installed in the clone cache (re-asserted before every turn; only console-managed clones, never user-selected repos) plus a prompt rule to keep the trailer. Market edition degrades to the prompt rule. Adds a search probe utility verifying the PR-title and commit-trailer queries against the GitHub search API.