Fix trade offer png generation (fixes #27).

- Updated `card_badge.html` to adjust width properties for better layout consistency.
- Modified `trade_offer_png.html` to change padding for improved visual appearance.
- Enhanced `bubble_up_trade_offer_updates` signal to delete cached images when related instances change, ensuring up-to-date content.
- Updated `TradeOfferPNGView` to pass the request context when rendering the template, improving compatibility with Django's template rendering.
- Refactored `render_trade_offer_png` to use constants for dimensions and improve readability, while also updating context handling for better integration.

trades/views.py

@@ -1,3 +1,4 @@
+from django.template import RequestContext
 from django.views.generic import DeleteView, CreateView, ListView, DetailView, UpdateView
 from django.views import View
 from django.urls import reverse_lazy
@@ -521,9 +522,13 @@ class TradeOfferPNGView(View):
             image_height = tag_context.get('image_height')
             if not image_width or not image_height:
                 raise ValueError("Could not determine image dimensions from tag_context")
-            html = render_to_string("templatetags/trade_offer_png.html", tag_context)
+            html = render_to_string(
+                "templatetags/trade_offer_png.html",
+                context=tag_context,
+                request=request
+            )
 
-            # if query string has "debug=true", render the HTML instead of the PNG
+            # if query string has "debug", render the HTML instead of the PNG
             if request.GET.get("debug") == "html":
                 return render(request, "templatetags/trade_offer_png.html", tag_context)