chore(deps): bump @langchain/community from 1.1.4 to 1.1.18

Bumps [@langchain/community](https://github.com/langchain-ai/langchainjs) from 1.1.4 to 1.1.18.
- [Release notes](https://github.com/langchain-ai/langchainjs/releases)
- [Commits](https://github.com/langchain-ai/langchainjs/compare/@langchain/community@1.1.4...@langchain/community@1.1.18)

---
updated-dependencies:
- dependency-name: "@langchain/community"
  dependency-version: 1.1.18
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

packages/ai-proxy/package.json

@@ -15,7 +15,7 @@
     "@forestadmin/agent-toolkit": "1.1.0",
     "@forestadmin/datasource-toolkit": "1.52.0",
     "@langchain/anthropic": "1.3.17",
-    "@langchain/community": "1.1.4",
+    "@langchain/community": "1.1.18",
     "@langchain/core": "1.1.15",
     "@langchain/langgraph": "^1.1.0",
     "@langchain/mcp-adapters": "1.1.1",