#4730 Docs: dashboard and history get name who started and decided a run by username

swamp-club#4676 (swamp PR 3791) has serve record the username it knows on a workflow run (initiatedByUsername) and on each approval decision (decidedByUsername). The dashboard run detail, its approval notes, its pending approvals list and swamp workflow history get now print user: when a name is recorded, and the principal id otherwise (token auth, old runs, local approvals, scheduled and webhook runs read as before). The --json view adds initiatedByUsername, approvedByUsername and rejectedByUsername beside the unchanged id fields.

Stale text: content/manual/reference/swamp-serve/dashboard.md line 192 says that after a decision the gate shows Approved by or Rejected by and the principal recorded as decidedBy. Suggested wording: the gate names the decider as user: when serve knew their username, and the recorded principal (decidedBy) otherwise.

Worth adding to the workflows reference: the three optional JSON fields, and that anyone who can read a run can read these names (unlike the audit log's principalUsername, which needs admin on access:audit).