docs(web-ui): address review

- hivectl/README.md: split matrix.rs/github.rs into accurate per-module
  lines (matrix.rs invites a matrix user to the hive Space/room,
  cli.rs:289-296; it is not per-agent). Fixed the summary line's
  'provisioning verbs' to name the actual verb groups left after the
  facts pass.
- web-ui/README.md: the swarm/ui.md pointer no longer promises roster/
  creating-agents/linking-accounts content that page doesn't have.
- Reverted the unrelated doesn't/does not drive-by at hivectl/README.md:5.

docs/web-ui/README.md

@@ -1,8 +1,7 @@
 # Dashboard & Web UI
 
 The per-hive dashboard: approvals, container state and the rebuild
-queue for one hive. For swarm-wide day to day — the agent roster,
-creating agents, linking accounts — see
+queue for one hive. For swarm-wide day to day, see
 [the swarm UI](../swarm/ui.md) instead. If you want implementation
 detail — wire formats, DOM structure, event plumbing — see [Dashboard
 layout](dashboard.md), [Per-agent page](agent.md), [Shape](shape.md),