docs: add /help hub and Node/npm PATH guide

docs/help/index.md

@@ -0,0 +1,20 @@
+---
+summary: "Help hub: common fixes, install sanity, and where to look when something breaks"
+read_when:
+  - You’re new and want the “what do I click/run” guide
+  - Something broke and you want the fastest path to a fix
+---
+
+# Help
+
+If you want a quick “get unstuck” flow, start here:
+
+- **Troubleshooting:** [Start here](/help/troubleshooting)
+- **Install sanity (Node/npm/PATH):** [Node.js + npm (PATH sanity)](/install/node)
+- **Gateway issues:** [Gateway troubleshooting](/gateway/troubleshooting)
+- **Logs:** [Logging](/logging) and [Gateway logging](/gateway/logging)
+- **Repairs:** [Doctor](/gateway/doctor)
+
+If you’re looking for conceptual questions (not “something broke”):
+
+- [FAQ (concepts)](/help/faq)