muster release v5.26.1

Fixed

• Plain muster auth login renews an expired stored ID token. The renewal decision hung on the handler’s status path, which reaches Authenticated only when the stored access token is valid for another minute by the CLI’s own reading and otherwise probes the server; the mcp-go transport connects with that same token regardless, so a session the aggregator accepted answered Already authenticated while the decision never saw the ID token (muster auth status then said No authentication required). The decision now reads the ID token’s exp from the token file alone, before the “already authenticated” answer and without a probe; a session without an ID token is renewed too. (#1268)