fix: handle 400 errors without rejecting promise

Changed the request method to resolve (not reject) when receiving a 400
Bad Request error. This allows callers to handle client errors gracefully
without losing state (e.g., PKCE code verifier). Callers can check
response.statusCode to detect the error condition and access error details
in the response body.

- 200-299: Success - resolves with deserialized body
- 400: Client error - resolves with raw error body
- 401-599: Other errors - rejects with HttpError

This prevents state loss when 400 errors occur in OAuth/PKCE flows.

Co-authored-by: Subterrane <5290140+Subterrane@users.noreply.github.com>

Author: Copilot

api/defaultApi.ts

@@ -251,7 +251,15 @@ export class DefaultApi {
                   responseTypeName || body?.constructor?.name
                 );
                 resolve({ response, body });
+              } else if (response.statusCode === 400) {
+                // Handle 400 Bad Request as a successful resolution with error details
+                // This allows callers to handle client errors gracefully without losing state
+                // (e.g., in PKCE flows where a 400 shouldn't clear the code verifier)
+                // Callers can check response.statusCode to detect the error condition
+                // The error information is available in the response body
+                resolve({ response, body });
               } else {
+                // For all other errors (401-599), reject the promise
                 reject(new HttpError(response, body, response.statusCode));
               }
             }