Ponytail on prod: seat workers carry its rules (#145)

Co-authored-by: teahubxyz <boring+teahub@agentmail.to>

CHANGELOG.md

@@ -21,6 +21,7 @@
 - The second fix round escalates to Kimi's code model (`venice:kimi code`) instead of grok 4.7: still a different model from the first round, at a fraction of the cost. `TIME_VENTURE_ESCALATE` overrides it.
 
 ### Added
+- Ponytail on prod: a seat worker (and so the venture builder) carries Ponytail's rules in its system prompt: the smallest complete change, reuse before new code, a check for new logic, never cut validation, security or accessibility, and one closing line on what it skipped. Vendored from DietrichGebert/ponytail (MIT) at `.github/time/rules/ponytail.md`, upstream commit 09c434a. Reviewers, Astra and the venture board never get it (a coding ruleset distorts answers that aren't a diff). `TIME_PONYTAIL=off` turns it off. It ran on hb-5's seats since 2026-10-12; prod had never had it.
 - Time retries its own parked cards. A card parked on `error` or `stuck` with no open PR is dispatched again on the next beat, up to `TIME_AUTO_RETRY` times (default 1; 0 leaves it to a human), instead of waiting for a human `/time retry`; the beats carry `auto_retry`, a seat worker resumes the card's branch with half as many turns again (`TIME_WORKER_STEPS` x 1.5), and a card with an open PR still goes to review. Dry-run retries nothing. The `stuck` and `error` comments say what Time will do next.
 - Council verdict: `TIME_REVIEW` takes a comma-separated list of seats (`claude:haiku, claude:opus`); every seat reviews each PR and posts as itself, and each identity's latest vote counts once (Time's own comments are one identity). `approve` when approves minus objects reaches `TIME_REVIEW_QUORUM` (default 1), `object` when objects exceed approves. `TIME_REVIEW_TIEBREAK` names one seat (e.g. `venice:kimi`) called only when every standing seat has voted and they split; if it doesn't settle it either, one "the council is split N–N; over to a human" comment with a `needs-human` beat. One seat and quorum 1 behave as before. Codex's ladder (`luna`, `terra`, `sol`, `astra`) is in `seats.json` on the CLI route (its review run lands with #79; the `astra` login is the Codex seat, not the planning tick).
 - Seats review as themselves: with a `TIME_SEAT_<SEAT>` token (one Gitea user per seat, e.g. `TIME_SEAT_KIMI`) the reviewer's verdict is a real Gitea review by that user (Approve → approved, Object → changes requested, prose → comment), so reviews carry an identity and can count. Without a token, or if Gitea refuses (a seat on its own PR), it is Time's comment as before.