docs: remove LGP mentions (#5780)

docs/docs/concepts/mcp.md

@@ -10,48 +10,3 @@ Install the `langchain-mcp-adapters` library to use MCP tools in LangGraph:
 pip install langchain-mcp-adapters
 ```
 
-## Authenticate to an MCP server
-
-You can set up [custom authentication middleware](../how-tos/auth/custom_auth.md) to authenticate a user with an MCP server to get access to user-scoped tools within your LangGraph Platform deployment.
-
-!!! note
-
-    Custom authentication is a LangGraph Platform feature.
-
-An example architecture for this flow:
-
-```mermaid
-sequenceDiagram
-  %% Actors
-  participant ClientApp as Client
-  participant AuthProv  as Auth Provider
-  participant LangGraph as LangGraph Backend
-  participant SecretStore as Secret Store
-  participant MCPServer as MCP Server
-
-  %% Platform login / AuthN
-  ClientApp  ->> AuthProv: 1. Login (username / password)
-  AuthProv   -->> ClientApp: 2. Return token
-  ClientApp  ->> LangGraph: 3. Request with token
-
-  Note over LangGraph: 4. Validate token (@auth.authenticate)
-  LangGraph  -->> AuthProv: 5. Fetch user info
-  AuthProv   -->> LangGraph: 6. Confirm validity
-
-  %% Fetch user tokens from secret store
-  LangGraph  ->> SecretStore: 6a. Fetch user tokens
-  SecretStore -->> LangGraph: 6b. Return tokens
-
-  Note over LangGraph: 7. Apply access control (@auth.on.*)
-
-  %% MCP round-trip
-  Note over LangGraph: 8. Build MCP client with user token
-  LangGraph  ->> MCPServer: 9. Call MCP tool (with header)
-  Note over MCPServer: 10. MCP validates header and runs tool
-  MCPServer  -->> LangGraph: 11. Tool response
-
-  %% Return to caller
-  LangGraph  -->> ClientApp: 12. Return resources / tool output
-```
-
-For more information, see [MCP endpoint in LangGraph Server](../concepts/server-mcp.md).

docs/docs/guides/index.md

@@ -31,15 +31,3 @@ These capabilities are available in both LangGraph OSS and the LangGraph Platfor
 - [MCP](../concepts/mcp.md): Use MCP servers in a LangGraph graph.
 - [Evaluation](../agents/evals.md): Use LangSmith to evaluate your graph's performance.
 
-## Platform-only capabilities
-
-These capabilities are only available in [LangGraph Platform](../concepts/langgraph_platform.md).
-
-- [Authentication and access control](../concepts/auth.md): Authenticate and authorize users to access a LangGraph graph.
-- [Assistants](../concepts/assistants.md): Build assistants that can be used to interact with a LangGraph graph.
-- [Double-texting](../concepts/double_texting.md): Handle double-texting (consecutive messages before a first response is returned) in a LangGraph graph.
-- [Webhooks](../cloud/concepts/webhooks.md): Send webhooks to a LangGraph graph.
-- [Cron jobs](../cloud/concepts/cron_jobs.md): Schedule jobs to run at a specific time.
-- [Server customization](../how-tos/http/custom_lifespan.md): Customize the server that runs a LangGraph graph.
-- [Data management](../cloud/concepts/data_storage_and_privacy.md): Manage data in a LangGraph graph.
-- [Deployment](../concepts/deployment_options.md): Deploy a LangGraph graph to a server.

docs/docs/reference/index.md

@@ -49,9 +49,8 @@ Higher-level abstractions for common workflows, agents, and other patterns.
 
 Tools for deploying and connecting to the LangGraph Platform.
 
-- [CLI](../cloud/reference/cli.md): Command-line interface for building and deploying LangGraph Platform applications.
-- [Server API](../cloud/reference/api/api_ref.md): REST API for the LangGraph Server.
 - [SDK (Python)](../cloud/reference/sdk/python_sdk_ref.md): Python SDK for interacting with instances of the LangGraph Server.
 - [SDK (JS/TS)](../cloud/reference/sdk/js_ts_sdk_ref.md): JavaScript/TypeScript SDK for interacting with instances of the LangGraph Server.
 - [RemoteGraph](remote_graph.md): `Pregel` abstraction for connecting to LangGraph Server instances.
-- [Environment variables](../cloud/reference/env_var.md): Supported configuration variables when deploying with the LangGraph Platform.
+
+See the [LangGraph Platform reference](https://docs.langchain.com/langgraph-platform/reference-overview) for more reference documentation.

docs/docs/troubleshooting/errors/index.md

@@ -11,11 +11,4 @@ Errors referenced below will have an `lc_error_code` property corresponding to o
 - [INVALID_CONCURRENT_GRAPH_UPDATE](./INVALID_CONCURRENT_GRAPH_UPDATE.md)
 - [INVALID_GRAPH_NODE_RETURN_VALUE](./INVALID_GRAPH_NODE_RETURN_VALUE.md)
 - [MULTIPLE_SUBGRAPHS](./MULTIPLE_SUBGRAPHS.md)
-- [INVALID_CHAT_HISTORY](./INVALID_CHAT_HISTORY.md)
-
-## LangGraph Platform
-
-These guides provide troubleshooting information for errors that are specific to the LangGraph Platform.
-
-- [INVALID_LICENSE](./INVALID_LICENSE.md)
-- [Studio Errors](../studio.md)
+- [INVALID_CHAT_HISTORY](./INVALID_CHAT_HISTORY.md)