docs: pin queue and stream limits

CAPABILITY-MAP.md

@@ -53,6 +53,8 @@ Build sequence: data foundation → identity and analytics → API → dashboard
 11. An idempotent start request enqueues overview, payment-performance, fees, and peer-comparison sections for bounded parallel calculation by a separate Go worker; Redis caches each typed section for 30 days under merchant/cohort and metric-definition revisions.
 12. A separate authenticated SSE request exposes each section as it becomes ready. Redis and the on-demand worker remain private, and Redis is never a source of truth or backup target.
 13. Each section attempt is limited to 60 seconds and at most two transient retries with exponential backoff/jitter; deterministic errors fail immediately.
+14. The worker pins pre-1.0 Asynq `v0.26.0`, runs at 16 jobs globally and 4/merchant by default, and changes require reviewed dependency/load evidence.
+15. Start, manual-retry, and SSE limits use independent authenticated-user/merchant buckets and return `429` with `Retry-After` before work is queued. SSE heartbeats run every 15 seconds and authorized run-event replay lasts one hour.
 
 ## Required capability specs