matrix-accounts dashboard: live status + homeserver from daemon snapshot (be-4)

hive-matrix-mcp/src/main.rs

@@ -103,6 +103,15 @@ async fn main() -> Result<()> {
         return Ok(());
     }
 
+    // Publish the live-account snapshot (BE-4) for the dashboard: the
+    // accounts that restored, with effective homeserver + user id. Lands
+    // in the host-visible state dir so hive-c0re reads it to show live
+    // up/down + backfill homeserver. Best-effort — a failed write must
+    // not stop the daemon from serving.
+    if let Err(e) = registry.write_snapshot(&paths::accounts_file()) {
+        tracing::warn!(error = %format!("{e:#}"), "failed to write matrix-accounts snapshot");
+    }
+
     // Serve the socket against the registry. Spawned before driving the
     // sync loops so the MCP bridge can connect as soon as the first
     // claude turn fires.