fix: taking plan type from usage endpoint instead of thru auth token (#7610)

pull plan type from the usage endpoint, persist it in session state /
tui state, and propagate through rate limit snapshots

codex-rs/core/src/error.rs

@@ -560,6 +560,7 @@ mod tests {
                 resets_at: Some(secondary_reset_at),
             }),
             credits: None,
+            plan_type: None,
         }
     }