* ci: cost cap + 3-model A/B harness on CTO reviewer
Two enhancements to the PR reviewer:
1. Monthly spend cap: tracked in Repo Variables (CTO_REVIEW_MONTH,
CTO_REVIEW_SPEND_CENTS, CTO_REVIEW_CAP_CENTS). Default cap $10/month.
Auto-resets on month rollover. Posts a skip-comment on PRs when cap hit.
2. A/B harness: reviews every PR with 3 models in parallel
(Claude Haiku 4.5, DeepSeek V3.1, Kimi K2 Thinking). Comment shows
all 3 verdicts side-by-side so we can compare quality/cost on real
PRs before picking a permanent default. Drop to 1 model by editing
the MODELS list after A/B window closes.
Agent-Session: cowork-reviewer-ab-20260414
* ci: use CTO_ADMIN_TOKEN for repo variables + restore formal APPROVE/REQUEST_CHANGES
Default GITHUB_TOKEN cannot mutate Repository Variables (always 403).
Use a PAT-backed secret CTO_ADMIN_TOKEN for the budget counter steps.
Also restores formal APPROVE/REQUEST_CHANGES verdicts now that repo
setting can_approve_pull_request_reviews is enabled.
Agent-Session: cowork-reviewer-ab-20260414
* ci: address review feedback — per-model timeout + simpler cost math
- Per-model timeout of 60s so one hung model does not block siblings
- Simplify cost_cents math (cost_usd * 100 directly, no double-rounding)
Defer: fine-grained PAT for CTO_ADMIN_TOKEN (requires manual OAuth device flow).
Agent-Session: cowork-reviewer-ab-20260414
* ci: stop exposing CTO_ADMIN_TOKEN as env var (security cleanup)
Pass the PAT only via github-token param. continue-on-error on the
budget step so a missing/expired secret degrades gracefully instead
of failing the whole workflow.
Agent-Session: cowork-reviewer-ab-20260414
e1efc20237