Wrap comment params for flat JSON payloads (#2679)

* Wrap comment params for flat JSON payloads

The SDK sends flat JSON ({"body": "..."}) but Rails wrap_parameters
auto-detection misses :body since it's a virtual ActionText attribute,
not in Comment.attribute_names. Explicitly declare wrap_parameters so
params.expect(comment: [...]) works with both wrapped and flat payloads.

* Test comment create and update with flat JSON params

app/controllers/cards/comments_controller.rb

@@ -1,4 +1,5 @@
 class Cards::CommentsController < ApplicationController
+  wrap_parameters :comment, include: %i[ body created_at ]
   include CardScoped
 
   before_action :set_comment, only: %i[ show edit update destroy ]