Refactor cloud requirements error and surface in JSON-RPC error (#14504)

Refactors cloud requirements error handling to carry structured error
metadata and surfaces that metadata through JSON-RPC config-load
failures, including:
* adds typed CloudRequirementsLoadErrorCode values plus optional
statusCode
* marks thread/start, thread/resume, and thread/fork config failures
with structured cloud-requirements error data

codex-rs/config/src/cloud_requirements.rs

@@ -6,18 +6,43 @@ use std::fmt;
 use std::future::Future;
 use thiserror::Error;
 
+#[derive(Clone, Copy, Debug, Eq, PartialEq)]
+pub enum CloudRequirementsLoadErrorCode {
+    Auth,
+    Timeout,
+    Parse,
+    RequestFailed,
+    Internal,
+}
+
 #[derive(Clone, Debug, Eq, Error, PartialEq)]
 #[error("{message}")]
 pub struct CloudRequirementsLoadError {
+    code: CloudRequirementsLoadErrorCode,
     message: String,
+    status_code: Option<u16>,
 }
 
 impl CloudRequirementsLoadError {
-    pub fn new(message: impl Into<String>) -> Self {
+    pub fn new(
+        code: CloudRequirementsLoadErrorCode,
+        status_code: Option<u16>,
+        message: impl Into<String>,
+    ) -> Self {
         Self {
+            code,
             message: message.into(),
+            status_code,
         }
     }
+
+    pub fn code(&self) -> CloudRequirementsLoadErrorCode {
+        self.code
+    }
+
+    pub fn status_code(&self) -> Option<u16> {
+        self.status_code
+    }
 }
 
 #[derive(Clone)]