Show an inline warning banner in the Add Node form when the user enters
an http:// URL, recommending HTTPS or VPN for public internet connections.
HTTP remains fully supported for private networks (LAN, VPN, VPC).
Also returns an optional `warning` field in POST/PUT /api/nodes responses
for API-only consumers, and expands the multi-node security documentation
with concrete deployment guidance (reverse proxy, VPN, private network).
- Add 5 new Tier 1 doc pages: configuration, stack-management, editor,
multi-node, and alerts-notifications
- Update introduction, quickstart, and features/overview to reflect
current feature set and link to new pages
- Restructure mint.json with Getting Started / Features / Reference /
Operations navigation groups
- Add Playwright-captured screenshots for all major UI screens