DrmTokenProvider

Supplies a DRM license token. Called on every license request — including renewals — so implementations must return a currently valid token each time (fetch it, refresh auth, etc.). Never cache a token beyond its lifetime; the SDK never caches it at all.

Invoked on a background thread with an 8s timeout and retries.

The timeout works through coroutine cancellation: implementations must be cancellable (suspending I/O such as OkHttp's await is; a raw blocking call inside the suspend function is not, and would hold the license request past the fence until it returns on its own).