Added MCP server command to enable authentication using ChatGPT (#2373)

This PR adds two new APIs for the MCP server: 1) loginChatGpt, and 2)
cancelLoginChatGpt. The first starts a login server and returns a local
URL that allows for browser-based authentication, and the second
provides a way to cancel the login attempt. If the login attempt
succeeds, a notification (in the form of an event) is sent to a
subscriber.

I also added a timeout mechanism for the existing login server. The
loginChatGpt code path uses a 10-minute timeout by default, so if the
user fails to complete the login flow in that timeframe, the login
server automatically shuts down. I tested the timeout code by manually
setting the timeout to a much lower number and confirming that it works
as expected when used e2e.

codex-rs/mcp-server/src/wire_format.rs

@@ -60,6 +60,15 @@ pub enum ClientRequest {
         request_id: RequestId,
         params: RemoveConversationListenerParams,
     },
+    LoginChatGpt {
+        #[serde(rename = "id")]
+        request_id: RequestId,
+    },
+    CancelLoginChatGpt {
+        #[serde(rename = "id")]
+        request_id: RequestId,
+        params: CancelLoginChatGptParams,
+    },
 }
 
 #[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Default)]
@@ -122,6 +131,36 @@ pub struct AddConversationSubscriptionResponse {
 #[serde(rename_all = "camelCase")]
 pub struct RemoveConversationSubscriptionResponse {}
 
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq)]
+#[serde(rename_all = "camelCase")]
+pub struct LoginChatGptResponse {
+    pub login_id: Uuid,
+    /// URL the client should open in a browser to initiate the OAuth flow.
+    pub auth_url: String,
+}
+
+// Event name for notifying client of login completion or failure.
+pub const LOGIN_CHATGPT_COMPLETE_EVENT: &str = "codex/event/login_chatgpt_complete";
+
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq)]
+#[serde(rename_all = "camelCase")]
+pub struct LoginChatGptCompleteNotification {
+    pub login_id: Uuid,
+    pub success: bool,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub error: Option<String>,
+}
+
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq)]
+#[serde(rename_all = "camelCase")]
+pub struct CancelLoginChatGptParams {
+    pub login_id: Uuid,
+}
+
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq)]
+#[serde(rename_all = "camelCase")]
+pub struct CancelLoginChatGptResponse {}
+
 #[derive(Serialize, Deserialize, Debug, Clone, PartialEq)]
 #[serde(rename_all = "camelCase")]
 pub struct SendUserMessageParams {