Add request spec variant exercising populated CommentsFeed

Existing /rsc_payload/ServerComponentsPage spec sent empty {} props,
which only exercises the empty-state branch of CommentsFeed. The new
variant passes a realistic comment so the marked + sanitize-html
markdown rendering path and the comment list mapping are covered.

Verified locally: 4/4 examples pass against the running renderer.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: ihabadham

spec/requests/server_components_spec.rb

@@ -32,6 +32,15 @@ def expect_valid_rsc_payload
       expect_valid_rsc_payload
     end
 
+    it "streams a valid RSC payload for ServerComponentsPage with populated comments" do
+      now = 1.minute.ago.iso8601
+      comments = [
+        { id: 1, author: "Alice", text: "Hello **markdown**", created_at: now, updated_at: now },
+      ]
+      get "/rsc_payload/ServerComponentsPage", params: { props: { comments: comments }.to_json }
+      expect_valid_rsc_payload
+    end
+
     it "streams a valid RSC payload for LiveActivity" do
       get "/rsc_payload/LiveActivity", params: { props: "{}" }
       expect_valid_rsc_payload