@onlyworlds/sdk 4.26.0

Added

• The door of every write (keel #299, D104; keel 7c1b493). An opt-in
  agent: true on OwClientConfig sends X-OW-Agent on every element write (create, upsert,
  patch, delete, editLinks, bulk: the operations keel's document declares it on; never on reads,
  account routes or the image edge); keel records such writes as declared, agent-made, and stores only that the header was
  there. Off by default: it describes the caller, so a tool people use never sets it.
• OwElementBase gains the read-only changed_by (the membership of the last write) and
  changed_via (its door: seat, mcp, declared, api, v1, sync, server); a /changes
  delete op gains deleted_by and deleted_via. Keel drops them from a write body, like created_by.
• OwWriteDoor, AGENT_DOORS and isAgentDoor(door): seat, mcp and declared are agent-made.
• The two kinds of /changes item are named types, OwChangeUpsert and OwChangeDelete (OwChange is their union, as before), and both declare change_seq, which keel always sends and the type never named.