The tool runner's bus account carried the heard grants, consumer and bind word of every module it runs, and every agent session on that machine reaches the bus as that account, so any session could pull a granted module's consumer on MAIL. Per ADR 0376 §1 the controller now composes a restricted stream's consumer, grants and bind word only for a module that declares runs-as; registration refuses a consumes of a restricted stream without runs-as (§2), and a grant that composes nothing is said in doctor (D-heard) and in the controller's log on every raise and send.
mesh-mail's events must live on a stream of their own and reach only the modules the operator granted
an account (ADR 0359 §2, §4). The controller now creates a module's declared stream, publishes its events
on mesh.stream.<module>.event.<event>, and composes a consumer's durable consumer, filters and bus grants
on a restricted stream only where its consumes asks and the provider's trusted value names it; a consumer
that loses its grant has its consumer removed on the next assertion. Nothing changes while no manifest
declares a stream.