Reliable MCP sign-in on scaled deployments

Connecting an MCP client to the portal could fail with an authorization error when the portal was running more than one replica — the sign-in would only succeed if two consecutive requests happened to reach the same server instance. Authorization codes are now stored in the mesh itself, so any replica can complete a sign-in started on any other. Codes remain single-use and short-lived, and interrupted sign-ins now fail fast with a clear error instead of hanging.

Reconnecting…
The connection to the server was interrupted. Trying to restore it…
Trying again…
The connection could not be restored. Reloading the page…
The server was updated. Reloading the page to pick up the latest version.