feat: add remote MCP endpoint for external agent access

- Add app/api/mcp/route.ts with read-only ls_* tools
- Tools: ls_search_nodes, ls_get_nodes, ls_query_edges, ls_list_dimensions
- Uses WebStandardStreamableHTTPServerTransport for Vercel serverless
- Stateless mode (sessionIdGenerator: undefined) for proper serverless execution
- CORS headers for cross-origin agent access
- GET endpoint returns server info for debugging

Usage: claude mcp add --transport http latent-space https://latentspace.ra-h.app/api/mcp

package.json

@@ -24,6 +24,7 @@
     "@ai-sdk/openai": "^3.0.7",
     "@langchain/core": "^1.0.1",
     "@langchain/textsplitters": "^1.0.1",
+    "@modelcontextprotocol/sdk": "^1.25.3",
     "@xyflow/react": "^12.10.0",
     "ai": "^6.0.27",
     "better-sqlite3": "^12.2.0",