fix: ensure every variant of ClientRequest has a params field (#4512)

This ensures changes the generated TypeScript type for `ClientRequest`
so that instead of this:

```typescript
/**
 * Request from the client to the server.
 */
export type ClientRequest =
  | { method: "initialize"; id: RequestId; params: InitializeParams }
  | { method: "newConversation"; id: RequestId; params: NewConversationParams }
  // ...
  | { method: "getUserAgent"; id: RequestId }
  | { method: "userInfo"; id: RequestId }
  // ...
```

we have this:

```typescript
/**
 * Request from the client to the server.
 */
export type ClientRequest =
  | { method: "initialize"; id: RequestId; params: InitializeParams }
  | { method: "newConversation"; id: RequestId; params: NewConversationParams }
  // ...
  | { method: "getUserAgent"; id: RequestId; params: undefined }
  | { method: "userInfo"; id: RequestId; params: undefined }
  // ...
```

which makes TypeScript happier when it comes to destructuring instances
of `ClientRequest` because it does not complain about `params` not being
guaranteed to exist anymore.

codex-rs/app-server/src/codex_message_processor.rs

@@ -193,28 +193,43 @@ impl CodexMessageProcessor {
             ClientRequest::LoginApiKey { request_id, params } => {
                 self.login_api_key(request_id, params).await;
             }
-            ClientRequest::LoginChatGpt { request_id } => {
+            ClientRequest::LoginChatGpt {
+                request_id,
+                params: _,
+            } => {
                 self.login_chatgpt(request_id).await;
             }
             ClientRequest::CancelLoginChatGpt { request_id, params } => {
                 self.cancel_login_chatgpt(request_id, params.login_id).await;
             }
-            ClientRequest::LogoutChatGpt { request_id } => {
+            ClientRequest::LogoutChatGpt {
+                request_id,
+                params: _,
+            } => {
                 self.logout_chatgpt(request_id).await;
             }
             ClientRequest::GetAuthStatus { request_id, params } => {
                 self.get_auth_status(request_id, params).await;
             }
-            ClientRequest::GetUserSavedConfig { request_id } => {
+            ClientRequest::GetUserSavedConfig {
+                request_id,
+                params: _,
+            } => {
                 self.get_user_saved_config(request_id).await;
             }
             ClientRequest::SetDefaultModel { request_id, params } => {
                 self.set_default_model(request_id, params).await;
             }
-            ClientRequest::GetUserAgent { request_id } => {
+            ClientRequest::GetUserAgent {
+                request_id,
+                params: _,
+            } => {
                 self.get_user_agent(request_id).await;
             }
-            ClientRequest::UserInfo { request_id } => {
+            ClientRequest::UserInfo {
+                request_id,
+                params: _,
+            } => {
                 self.get_user_info(request_id).await;
             }
             ClientRequest::FuzzyFileSearch { request_id, params } => {