Embassy v4.4.1

Embassy 4.4.1 — documentation

No code change from 4.4.0. The shipped documentation now describes the current product in the present tense: README is a newcomer's path (install, start the broker, see the agents, send, reply, federate, retire) with embassy tui as the daily view; history scaffolding and references to removed features are gone except in the upgrade sections kept for 3.x users; protocol and schema numbers are stated once each and match the source (private state schema 7 with the schema-6 forward read, private control 6, federation 3); issue and pull-request templates match the CLI that ships. Every claim was traced to code before release.

Upgrading — install and restart the broker; no state change.

Tested with offline suite 408/408 on Node 22 (macOS and Ubuntu).