json dataclass RedeemResult serialization issues

[timnbraun]

I'm trying to get this to work with my django 6.0.4 based web site, and the following issues have been seen:

1. The API doesn't end with a slash - normal for web APIs. But this triggers an error "RuntimeError: You called this URL via POST, but the URL doesn't end in a slash..." if APPEND_SLASH is set. I editted the url.py to accept no trailing slash and found the next error. This also required @no_append_slash decorations on the views in the api.
2. The CSRF token is not passed, perhaps due to using JSON instead of HTTP responses? I added the @csrf_exempt decorators to the views in the api and then found out the next error.
3. The redeem view ends with a:
   Bad Request: /cap/v1/redeem
   [11/Jun/2026 21:31:48] "POST /cap/v1/redeem HTTP/1.1" 400

[timnbraun]

I did some debugging on this and found there are two issues:

1. The RedeemResult class in cap_core/utils.py isn't serializable to Json as it exists. At least not with python 3.12.
   I fixed the issue by adding an asdict() method to RedeemResult and requesting that in the redeem_challenge() method in views.py.

2. API endpoints with slashes don't work with CSRF since the cap.js doesn't use slashes at the API endpoint names, and the redirects break the CSRF. I added decorators to avoid appending the slash on the API endpoints, and tweaked the urls.py to drop the slashes.

I'll clone the repo and generate a pull request.

[timnbraun]

Pull request has been generated. I hope it's acceptable. Thanks for the work you have done on this, it's a nice way to get some bot protection on a django website with a contact form!