New per-row action on AgentsPage: a quiet-variant icon badge (LinkIcon,
matching the LinksMenu/SettingsMenu chrome-not-chip convention) opens a
dialog with an account/token/homeserver form, PUTting
/api/hives/{hive}/agents/{agent}/matrix-accounts/{account} per the
contract atlas posted on hyperhive#3726 (issuecomment-72355).
Built against the contract before the backend endpoint exists per
atlas's explicit note that it doesn't change when the implementation
lands -- this 404s until that item merges. No linked-accounts list:
no route exposes one, and a credential store shouldn't hand a secret
back out anyway, so this is a blind set/update action, matching
mara's 1:1-for-now ruling on the issue.
Verified: tsc --noEmit and nix fmt clean, esbuild build clean. Real
DOM-interaction screenshots against a throwaway mock server (deleted
before this commit, never tracked) -- table column render + disabled
state on a hiveless row, dialog open, form filled with the token
masked, and the success path end to end (token field clears, success
message shows) against a mocked 200 response.
767f87610a