feat(showcase/google-adk/reasoning-default): rename from reasoning-default-render and port frontend from langgraph-python

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

Author: tylerslaton

showcase/integrations/google-adk/src/app/demos/reasoning-default-render/page.tsx

@@ -0,0 +1,35 @@
+"use client";
+
+// Reasoning — Default
+//
+// Pairs with `reasoning-custom` (the Custom variant) so users can
+// compare default vs custom reasoning rendering side by side. This cell
+// renders <CopilotChat> with NO slot override — reasoning messages are
+// rendered by the built-in `CopilotChatReasoningMessage` component
+// (Thinking… / Thought for X header with an expandable content region).
+//
+// Both demos share the same backend (`reasoning_agent` graph) and the
+// same runtime URL (/api/copilotkit). The only difference is whether the
+// `messageView.reasoningMessage` slot is overridden.
+
+import { CopilotKit, CopilotChat } from "@copilotkit/react-core/v2";
+import { useReasoningDefaultSuggestions } from "./suggestions";
+
+const AGENT_ID = "reasoning-default";
+
+export default function ReasoningDefaultDemo() {
+  return (
+    <CopilotKit runtimeUrl="/api/copilotkit" agent={AGENT_ID}>
+      <div className="flex justify-center items-center h-screen w-full">
+        <div className="h-full w-full max-w-4xl">
+          <Chat />
+        </div>
+      </div>
+    </CopilotKit>
+  );
+}
+
+function Chat() {
+  useReasoningDefaultSuggestions();
+  return <CopilotChat agentId={AGENT_ID} className="h-full rounded-2xl" />;
+}

showcase/integrations/google-adk/src/app/demos/reasoning-default/page.tsx

@@ -0,0 +1,22 @@
+"use client";
+
+import { useConfigureSuggestions } from "@copilotkit/react-core/v2";
+
+// Suggestions registered via the v2 chat composer hook. The prompt is a
+// concrete reasoning-eliciting question — gpt-5-mini (and other OpenAI
+// reasoning models) only emit `response.reasoning_summary_text.delta`
+// events when there's a real problem to think about. Meta-prompts like
+// "show your reasoning" produce no reasoning summary, so the reasoning
+// slot would never light up.
+export function useReasoningDefaultSuggestions() {
+  useConfigureSuggestions({
+    suggestions: [
+      {
+        title: "Show reasoning",
+        message:
+          "Explain step by step why the sky appears blue during the day but red at sunset.",
+      },
+    ],
+    available: "always",
+  });
+}