feat: Add support for Arcade videos on articles (#10585)

Fixes
https://linear.app/chatwoot/issue/CW-3779/add-support-for-arcade-videos-on-articles-loom-alternative

**Loom video**

https://www.loom.com/share/917bdecb4eaf4d3f9782b4fa84ee4bd4?sid=d11f0d71-0cf5-424a-9268-9d9fb3797ee2


Co-authored-by: Sojan Jose <sojan@pepalo.com>

spec/lib/custom_markdown_renderer_spec.rb

@@ -137,5 +137,33 @@ describe CustomMarkdownRenderer do
         expect(output).to include('src="https://player.vimeo.com/video/1234567"')
       end
     end
+
+    context 'when link is an Arcade URL' do
+      let(:arcade_url) { 'https://app.arcade.software/share/ARCADE_ID' }
+
+      it 'renders an iframe with Arcade embed code' do
+        output = render_markdown_link(arcade_url)
+        expect(output).to include('src="https://app.arcade.software/embed/ARCADE_ID"')
+        expect(output).to include('<iframe')
+        expect(output).to include('webkitallowfullscreen')
+        expect(output).to include('mozallowfullscreen')
+        expect(output).to include('allowfullscreen')
+      end
+
+      it 'wraps iframe in responsive container' do
+        output = render_markdown_link(arcade_url)
+        expect(output).to include('position: relative; padding-bottom: 62.5%; height: 0;')
+        expect(output).to include('position: absolute; top: 0; left: 0; width: 100%; height: 100%;')
+      end
+    end
+
+    context 'when multiple links including Arcade are present' do
+      it 'renders Arcade embed along with other content types' do
+        markdown = "\n[arcade](https://app.arcade.software/share/ARCADE_ID)\n\n[youtube](https://www.youtube.com/watch?v=VIDEO_ID)\n"
+        output = render_markdown(markdown)
+        expect(output).to include('src="https://app.arcade.software/embed/ARCADE_ID"')
+        expect(output).to include('src="https://www.youtube.com/embed/VIDEO_ID"')
+      end
+    end
   end
 end