The matrix, forge and github link routes wrote their credential
unconditionally, so linking a name that was already linked replaced the
working account. For matrix that lost the device the agent's crypto store
belongs to (#4838).
Each route now reads the account's store path first and answers 409,
naming the existing account, when something is stored there. Nothing is
written. Replacing an account takes the delete from #4899, then a link.
The matrix route checks before password mode's login, so a refused link
mints no new device at the homeserver.
The check is a read then a write, not an atomic step; two concurrent
links to one name can still both pass it.
Closes#4856
Each row of an agent's linked accounts, except its own `main` matrix
account, gets a delete action. swarm-controller serves DELETE beside each
PUT (matrix-accounts/{account}, forge-accounts/{label}, github-account),
answers 404 for an account the store does not hold, refuses `main`, and
removes every version through `delete_all_versions`.
The matrix confirmation has a revoke checkbox, off by default: the
controller logs the stored token out at its homeserver first, and keeps
the account when that fails or no homeserver is stored.
The controller's policy gains `delete` on each agent's
`metadata/.../matrix/+`, `forge/+` and `github-token`, pinned in
bao-grants.nix.
Refs #4855
The detail panel makes one request for the agent it shows,
GET /api/hives/{hive}/agents/{agent}/linked-accounts, which returns every
matrix, forge and github account of that agent as names and hosts. The
all-agents route and the table's matrix-column rows are removed, so the
table makes no linked-accounts request. The panel stays keyed by
hive/agent. The bao grant is unchanged.
Refs #4855
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
GET /api/hives/{hive}/agents/{agent}/linked-accounts returns one row per
account linked to the agent, as kind, name and host: each matrix account
under swarm/agents/<agent>/matrix (with its homeserver, and the agent's own
`main` marked reserved), each forge label under swarm/agents/<agent>/forge
(with its url), and github when swarm/agents/<agent>/github-token exists
(host github.com, which is not stored). No credential field is in the
response type.
Listing those two directories needs a new controller grant: `list` on
secret/metadata/swarm/agents/+/matrix and .../+/forge only, pinned in
bao-grants.nix as the only metadata stanzas under agents/ beside the queue
revocation. Checked against a dev OpenBao 2.6.3: the grant lists those two
directories and is refused on agents/, agents/<agent>/, and a leaf.
The swarm UI agent detail panel shows all rows under "accounts"; the table
view's matrix column shows the matrix rows. The link badges stay.
Refs #4855
