change model cap to server overload (#11388)

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

@@ -27,6 +27,7 @@
           "enum": [
             "contextWindowExceeded",
             "usageLimitExceeded",
+            "serverOverloaded",
             "internalServerError",
             "unauthorized",
             "badRequest",
@@ -36,35 +37,6 @@
           ],
           "type": "string"
         },
-        {
-          "additionalProperties": false,
-          "properties": {
-            "modelCap": {
-              "properties": {
-                "model": {
-                  "type": "string"
-                },
-                "reset_after_seconds": {
-                  "format": "uint64",
-                  "minimum": 0.0,
-                  "type": [
-                    "integer",
-                    "null"
-                  ]
-                }
-              },
-              "required": [
-                "model"
-              ],
-              "type": "object"
-            }
-          },
-          "required": [
-            "modelCap"
-          ],
-          "title": "ModelCapCodexErrorInfo",
-          "type": "object"
-        },
         {
           "additionalProperties": false,
           "properties": {