Reconcile the branch with main's landed behaviour on top of the rebase:
- Adopt main's hosting:auth:as:register-echo entry over the branch's
register-echo-application-type entry and its now-closed divergence, drop
the stale pinning test that superseded it, and remove its unused imports.
- Rewrite the no-further-notifications cancellation test onto the
doomed-call pattern: a cancelled request is no longer answered, so the
call is parked and abandoned instead of expecting an error, tolerating
only the legacy streamable HTTP terminator.
- Reword the no-further-notifications note to match the narrowed
in-flight divergence.
- Assert the persisted application_type echo in the DCR pass-through
test now that the registration echo carries it.
No-Verification-Needed: test-only diff, no runtime surface to drive
Max Isbey
52392f26cd