docs(cta): extend prebuilt-components and Built-in Agent placements

Adds a sign-up CTA to the shared `prebuilt-components` snippet so it
appears on all twelve per-integration `/{framework}/prebuilt-components`
pages that consume it, and adds a matching CTA to the LangGraph
prebuilt-components page (which uses custom content rather than the
shared snippet).

Moves the Built-in Agent overview CTA from below the features grid to
above the first H2 so it lands above the fold on standard viewports.

Author: samjulien

docs/content/docs/integrations/built-in-agent/index.mdx

@@ -9,6 +9,14 @@ The **Built-in Agent** is CopilotKit's simplest agent option, i.e what you get "
 
 It supports most popular models from OpenAI, Anthropic, Google, and AI-SDK defined models out of the box
 
+<OpsPlatformCTA
+  variant="card"
+  title="Ship the Built-in Agent to production"
+  body="Add persistent threads, observability, and the inspector with the CopilotKit platform."
+  ctaLabel="Create a free account"
+  surface="docs:built-in-agent:top"
+/>
+
 ## When to use Built-in Agent
 
 - **Quick setup** — no external agent framework to configure or deploy
@@ -33,14 +41,6 @@ If you need more control over your agent loop, consider using an [agent framewor
   <Card title="Custom Agent" href="/built-in-agent/custom-agent" description="Bring your own AI SDK, TanStack AI, or custom LLM backend." icon={<Blocks className="text-primary" />} />
 </Cards>
 
-<OpsPlatformCTA
-  variant="card"
-  title="Ship the Built-in Agent to production"
-  body="Add persistent threads, observability, and the inspector with the CopilotKit platform."
-  ctaLabel="Create a free account"
-  surface="docs:built-in-agent:after-features"
-/>
-
 ## Getting Started
 
 Head to the [Quickstart](./quickstart) to set up a working Built-in Agent in minutes.

docs/content/docs/integrations/langgraph/prebuilt-components.mdx

@@ -13,6 +13,13 @@ CopilotKit ships three prebuilt chat components that connect directly to your La
   If you've completed the [quickstart](/langgraph/quickstart), you already have one of these set up.
 </Callout>
 
+<OpsPlatformCTA
+  variant="inline"
+  title="Want users to resume conversations across sessions?"
+  body="Persistent threads ship with the CopilotKit platform. Try it for free."
+  surface="docs:langgraph/prebuilt-components:inline"
+/>
+
 <IframeSwitcher
   id="agentic-chat-example"
   exampleUrl="https://feature-viewer.copilotkit.ai/langgraph/feature/agentic_chat?sidebar=false&chatDefaultOpen=false"

docs/snippets/shared/basics/prebuilt-components.mdx

@@ -6,6 +6,13 @@ CopilotKit ships three prebuilt chat components that connect directly to your ag
   If you've completed the quickstart, you already have one of these set up.
 </Callout>
 
+<OpsPlatformCTA
+  variant="inline"
+  title="Want users to resume conversations across sessions?"
+  body="Persistent threads ship with the CopilotKit platform. Try it for free."
+  surface="docs:prebuilt-components:inline"
+/>
+
 <IframeSwitcher
   id="agentic-chat-example"
   exampleUrl={`https://feature-viewer.copilotkit.ai/${props.framework || "langgraph"}/feature/agentic_chat?sidebar=false&chatDefaultOpen=false`}