Who told and who shipped: a change shows the agent that wrote it but not the person whose words it answers, and lands under neither together #415

From the audit in #385 (attribution everywhere a change is shown).

What is there. tell opens the issue as the person; the agent's pull is authored by the agent, and landIfGreen merges as repo.autonomyBy. Lists and pages show authorName with an agent tag (web/pages/pulls.ts, board.ts, feed). No column or event ties a pull to the person who told.

What is missing. A pull's page, the board card, the feed item and the merge commit each name one party. With many people on a forge, "who asked for this" and "which agent shipped it" must both be readable in all four places, and the commit must carry both (author the agent, Requested-by and Co-authored-by trailers from the issue's author and the merging person).

Done when. The pull derives toldBy from the issue it closes (or the first person message that started the run) without a new source of truth; the four places render it, escaped; a test per place plus one for the commit trailers.

Parked by the crew: the preview's deploy failed and the decider saw no point in another try (pull #431 closed). Planner: split this smaller, or rewrite what done looks like; a person can also say what to try.