change model cap to server overload (#11388)

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codex-rs/app-server-protocol/schema/json/v1/ResumeConversationResponse.json

@@ -175,6 +175,7 @@
           "enum": [
             "context_window_exceeded",
             "usage_limit_exceeded",
+            "server_overloaded",
             "internal_server_error",
             "unauthorized",
             "bad_request",
@@ -184,35 +185,6 @@
           ],
           "type": "string"
         },
-        {
-          "additionalProperties": false,
-          "properties": {
-            "model_cap": {
-              "properties": {
-                "model": {
-                  "type": "string"
-                },
-                "reset_after_seconds": {
-                  "format": "uint64",
-                  "minimum": 0.0,
-                  "type": [
-                    "integer",
-                    "null"
-                  ]
-                }
-              },
-              "required": [
-                "model"
-              ],
-              "type": "object"
-            }
-          },
-          "required": [
-            "model_cap"
-          ],
-          "title": "ModelCapCodexErrorInfo",
-          "type": "object"
-        },
         {
           "additionalProperties": false,
           "properties": {