create-dmail crashes with 'Invalid parameter: list' when cc is omitted

[macterra]

Bug

keymaster create-dmail msg.json throws Invalid parameter: list when the JSON file omits the cc field.

Reproduction

{
  "to": ["did:cid:bagaaierac4tqrytzylxocfyq5p5uwjpk6ks6siapfuuswkq72fkboklt6b5a"],
  "subject": "Re: test",
  "body": "RSVP confirmed.",
  "reference": "did:cid:bagaaierai65e55vypijmw5r5s512dd7hf2vhptx41auudtebzowr3kayilma"
}

$ keymaster create-dmail msg.json
Invalid parameter: list

Cause

verifyDmail() passes message.cc directly to verifyRecipientList(). When cc is not present in the JSON, message.cc is undefined. verifyRecipientList checks Array.isArray(list), which fails for undefined.

https://github.com/archetech/archon/blob/main/packages/keymaster/src/keymaster.ts#L4368-L4369

Fix

Default cc to [] in verifyDmail before passing to verifyRecipientList:

const cc = await this.verifyRecipientList(message.cc || []);

Reported in v0.4.7.