dashboard: POST /matrix-account-login + account-aware hive-priv matrix-token write (BE-2)

hive-c0re/src/priv_client.rs

@@ -253,14 +253,21 @@ pub async fn write_agent_forge_token(agent_name: &str, token: &str) -> Result<()
     .await?)
 }
 
-/// Write the Matrix access token for `agent_name` to
-/// `<agent_state_root>/<agent_name>/state/matrix-token` via hive-priv
-/// (running as root). The file is written 0600 and chowned to the agent
-/// user so it is readable from inside the agent container.
-pub async fn write_agent_matrix_token(agent_name: &str, token: &str) -> Result<()> {
+/// Write a Matrix access token for `agent_name` via hive-priv (running as
+/// root). `account: None` writes the hive-internal
+/// `<state>/matrix-token`; `account: Some(name)` writes
+/// `<state>/matrix-token-<name>` for an extra (external) account. The file
+/// is written 0600 and chowned to the agent user so it is readable from
+/// inside the agent container. hive-priv validates the account suffix.
+pub async fn write_agent_matrix_token(
+    agent_name: &str,
+    token: &str,
+    account: Option<&str>,
+) -> Result<()> {
     ok(call(&PrivRequest::WriteAgentMatrixToken {
         agent_name: agent_name.to_owned(),
         token: token.to_owned(),
+        account: account.map(ToOwned::to_owned),
     })
     .await?)
 }