- blast-radius: getHeldMessages called with same start/end window as
searchDeliveredMessages
- blast-radius: unrelated-sender held row excluded from held/matched and
perRecipient; matching-sender held row still counts and overrides
- client: getHeldMessages threads start/end into POST body data[0] when
provided, omits them when not
Covers the already-implemented per-tenant factory: returns a MimecastClient
instance, builds a new independent instance per call (never the cached
global), doesn't affect getMimecastClient()'s singleton, and defaults
base_url when omitted. Uses fake credentials only.
- Add isMimecastConfigured() to lib/services/mimecast-client.ts mirroring
the pax8-factory.ts is<Name>Configured() convention
- Add _resetMimecastClient() test seam so tests can isolate env-var state
- Add lib/services/mimecast-client.test.ts covering config gate + throw/cache
behavior of getMimecastClient()
