feat(js-integrations): langgraph docs (#15507)

Author: obostjancic

docs/platforms/javascript/common/configuration/integrations/langgraph.mdx

@@ -0,0 +1,69 @@
+---
+title: LangGraph
+description: "Adds instrumentation for LangGraph."
+supported:
+  - javascript.node
+  - javascript.aws-lambda
+  - javascript.azure-functions
+  - javascript.connect
+  - javascript.express
+  - javascript.fastify
+  - javascript.gcp-functions
+  - javascript.hapi
+  - javascript.hono
+  - javascript.koa
+  - javascript.nestjs
+  - javascript.electron
+  - javascript.nextjs
+  - javascript.nuxt
+  - javascript.solidstart
+  - javascript.sveltekit
+  - javascript.react-router
+  - javascript.remix
+  - javascript.astro
+  - javascript.bun
+  - javascript.tanstackstart-react
+  - javascript.cloudflare
+---
+
+<Alert>
+
+This integration requires SDK version `10.25.0` or higher.
+
+</Alert>
+
+_Import name: `Sentry.langChainIntegration`_
+
+LangGraph is instrumented via the [`langChainIntegration`](./langchain), which automatically captures spans for LangGraph operations including agent invocations, graph executions, and node operations.
+
+## Usage Example
+
+```javascript
+import { ChatOpenAI } from "@langchain/openai";
+import { createReactAgent } from "@langchain/langgraph/prebuilt";
+import { HumanMessage, SystemMessage } from "@langchain/core/messages";
+
+// Create LLM and agent
+const llm = new ChatOpenAI({
+  modelName: "gpt-4o",
+  apiKey: process.env.OPENAI_API_KEY,
+});
+
+const agent = createReactAgent({ llm, tools: [] });
+
+// Invoke the agent - automatically instrumented
+const result = await agent.invoke({
+  messages: [
+    new SystemMessage("You are a helpful assistant."),
+    new HumanMessage("Hello!"),
+  ],
+});
+```
+
+## Configuration
+
+For configuration options, runtime-specific setup, and detailed information, see the [LangChain integration documentation](/platforms/javascript/guides/node/configuration/integrations/langchain/).
+
+## Supported Versions
+
+- `@langchain/langgraph`: `>=0.2.0 <1.0.0`