Add workspace-owner credit nudge flow to the CLI.

Expose workspace-owner account metadata and an app-server nudge endpoint so users who run out of credits can inspect usage and notify their workspace owner directly from the TUI.

Made-with: Cursor

codex-rs/app-server-protocol/schema/json/v2/AccountUpdatedNotification.json

@@ -55,6 +55,12 @@
         }
       ]
     },
+    "isWorkspaceOwner": {
+      "type": [
+        "boolean",
+        "null"
+      ]
+    },
     "planType": {
       "anyOf": [
         {