Address review feedback on Node 24 standardization

Refs: #40
- Align @types/node with Node 24 major (^24.0.0)
- Add root .nvmrc declaring Node 24
- Harden INSTALLATION.md to require Node 24 for local UI dev

.nvmrc

@@ -0,0 +1 @@
+24

INSTALLATION.md

@@ -16,7 +16,7 @@ Open SWE has two runnable pieces:
 - [uv](https://docs.astral.sh/uv/) package manager
 - [LangGraph CLI](https://docs.langchain.com/langsmith/cli)
 - [ngrok](https://ngrok.com/) (for local development — exposes webhook endpoints to the internet)
-- [pnpm](https://pnpm.io/) (only if you want to run the dashboard UI locally — see step 8). Node 24 is the recommended standard; older Node may work but is unsupported. `ui/pnpm-lock.yaml` is the canonical lockfile.
+- [pnpm](https://pnpm.io/) (only if you want to run the dashboard UI locally — see step 8). Node 24 is required; `ui/pnpm-lock.yaml` is the canonical lockfile.
 
 ## 1. Clone and install
 

ui/package.json

@@ -51,7 +51,7 @@
     "@tanstack/eslint-config": "^0.4.0",
     "@testing-library/dom": "^10.4.1",
     "@testing-library/react": "^16.3.2",
-    "@types/node": "^26.0.1",
+    "@types/node": "^24.0.0",
     "@types/react": "^19.2.14",
     "@types/react-dom": "^19.2.3",
     "@vitejs/plugin-react": "^6.0.3",