GET /api/agents/linked-accounts returns one entry per agent that
/api/agents/status has a row for, as {hive, agent, accounts}, from one
store login. The agents page fetches it once (and again when a link dialog
closes) and hands each table row and the detail panel its agent's slice,
so the page makes no per-agent request. The per-agent route had no caller
left and is removed. The bao grant is unchanged: the same list on each
agent's matrix and forge metadata directories.
Refs #4855
7ccde4647b