Fix Applications.Filter(Async) methods sending incorrect JSON body format

[Copilot]

The Applications.Filter and Applications.FilterAsync methods were sending an incorrectly formatted JSON body to the ARI server, which prevented event filtering from working properly.

Problem

When calling these methods with a filter object like:

await client.Applications.FilterAsync(appName, new
{
    allowed = new[]
    {
        new { type = "ChannelCreated" }
    }
});

The library was sending:

{"filter":{"allowed":[{"type":"ChannelCreated"}]}}

But according to the Asterisk ARI documentation, the expected format should be:

{"allowed":[{"type":"ChannelCreated"}]}

This caused the event filter to be ignored, and ARI would continue sending all events regardless of the filter configuration.

Solution

Removed the unnecessary wrapper object from both methods. Changed:

request.AddParameter("application/json", new { filter = filter }, ParameterType.RequestBody);

To:

request.AddParameter("application/json", filter, ParameterType.RequestBody);

This ensures the filter object is serialized directly as the root JSON object, matching the expected ARI API format.

Testing

• Verified the JSON output now matches the expected format
• Confirmed complex filters with both allowed and disallowed arrays work correctly
• Validated that null filter handling remains unchanged
• All builds and sample projects continue to work without issues

Fixes #82.

---

✨ Let Copilot coding agent set things up for you — coding agent works faster and does higher quality work when set up for your repo.

[Copilot]

@seiggy 👋 This repository doesn't have Copilot instructions. With Copilot instructions, I can understand the repository better, work faster and produce higher quality PRs.

I can generate a .github/copilot-instructions.md file for you automatically. Click here to open a pre-filled issue and assign it to me. I'll write the instructions, and then tag you for review.