266 — Federated quota capture

Where the last PR left the goal

synlynk could price a job in cost_entries and could store a hand-entered ceiling in harness_quotas. It could not see which subscription was actually near its weekly limit, so PM and review work kept landing on whichever harness was home.

What moved

The home harness hit 98% of its weekly quota during roadmap work. Allocation has to read the provider's own percent, not a local token estimate. Open-source usage tools were checked and rejected because they label their figures as API-equivalent estimates.

What this PR ships

quota_snapshots (migration 20) stores harness, window (5h or weekly), used_percent, resets_at, captured_at, source (task_boundary or poller), staleness_seconds, and job_id. The registry in synlynk/quota_capture.py maps Claude and Agy to cli -p "/usage" --output-format text, Codex to the newest payload.rate_limits object under ~/.codex/sessions, and Grok to billing: fetched credits config in ~/.grok/logs/unified.jsonl. Boundary capture runs on a daemon thread after exec_command and after a dispatch job settles done. The daemon poller runs every 15 minutes. For Grok it sends /usage and Enter into interactive_pane_id only when that id is set and the log line is older than 15 minutes. synlynk quota federated prints the latest row per harness and window next to a 7-day cost_entries sum. A reading older than 30 minutes, or a missing reading, is unknown. Unknown falls back to synlynk quota calibrate data in harness_quotas. Unpinned dispatch then prefers the known weekly reading with the most room, and skips a harness whose known 5h reading is at least 100%.

Brainstorm

No new brainstorm visuals. The approved spec is docs/superpowers/specs/2026-10-10-federated-quota-capture-design.md.

On the way to autonomous dispatch

The fleet can now see subscription headroom the same way it already sees dollar burn. Grok stays unknown until a standing Herdr pane id is registered. That pane setup is a separate design.

The new goalpost

Per-harness persistent Herdr panes, so Grok's weekly percent refreshes without a manual calibrate, and Herdr's place as a synlynk dependency gets its own spec.