fix: double slash in Proxmox network node list API endpoint

[t0kubetsu]

Problem

The Proxmox network node list endpoint in src/services/proxmox/api.ts contains a typo that produces a malformed URL:

// line 427
return query('/v0/admin/proxmox/network//node/list', { proxmox_node: node })
//                                      ^^ double slash

This causes a 404 on every call to network.listNodeInterfaces() because the backend receives a path with a double slash that does not match any route.

Expected

return query('/v0/admin/proxmox/network/node/list', { proxmox_node: node })

Impact

All calls to retrieve node-level network interfaces silently fail at runtime.