* Cover the ids a send gets back where the SMSC named only some of them
* Say undefined where the SMSC named no id for a segment it took
* Record why the merger takes the wider type, and de-duplicate the interop narrowing
* Guard the numbering hole the merger must refuse, and correct the phase record
* Regression tests: a PDU the codec cannot read costs that PDU, not the link
* Refuse a single unreadable PDU instead of the whole link
* smscsim interop asserts the first attempt gets every DLR
* Record the smscsim sequence number defect as fixed
* One framing rule and one response-command lookup, per the architecture review
* Apply the stability review's nits: honest sessionError docs and one link-survives assertion
lilleman