Fix reset_password to handle wrapped API response (#406)

The WorkOS API returns password reset responses in wrapped format
{"user": {...}} rather than a flat user object. This caused
reset_password to return a User object with all nil fields despite
successful API calls.

Changes:
- Updated reset_password to use UserResponse.new(response.body).user
  to correctly unwrap the API response (line 872)
- Updated VCR cassette to match current API response format

Verified:
- Tested against real WorkOS API with local code changes
- User object now correctly populated with all fields
- All 119 user_management tests pass
- Response format matches Go and Node.js SDK implementations
- Resolves customer issue where password reset succeeded but
  returned User object with all null fields

Author: nicknisi

lib/workos/user_management.rb

@@ -869,7 +869,7 @@ def reset_password(token:, new_password:)
           ),
         )
 
-        WorkOS::User.new(response.body)
+        WorkOS::UserResponse.new(response.body).user
       end
 
       # Get an Organization Membership