- declare rate + concurrency limits on every route and driver that lacked one
- add acquireConcurrent for websocket connections and the DAV mount
- bucket AI models by identity key only; keep resold duplicates of any vendor
- skip recently-failed provider routes; cap the fallback chain at 3 attempts
- let full-access access tokens bind a worker to an app their own user owns
- cache resolved subscriptions so tiered limits don't add a round trip
