Bug Description

The getLocalIp() helper function in websocket.ts naively iterates through network interfaces and returns the first non-internal IPv4 address it finds.

On developer machines, this often results in selecting a virtual interface IP (e.g., Docker 172.17.0.1, VMWare, or VPN adapters) instead of the actual Wi-Fi LAN IP (e.g., 192.168.x.x).

Steps to Reproduce

1. Run the application on a machine that has Docker or a VPN installed.
2. Go to the Settings page in the frontend.
3. Scan the generated QR code with a mobile device.
4. Result: The mobile device fails to connect because it is trying to reach an internal/virtual IP address that is not accessible from the phone.

Expected Behavior

1. The server should filter for the most likely LAN interface (e.g., usually 192.168.* or 10.*).
2. Alternatively, the server should send a list of all valid candidates to the frontend, and the Settings UI should allow the user to select the correct IP from a dropdown if the auto-detection is wrong.

Desktop Operating System

macOS (Apple Silicon)

Mobile Device (Client)

Vivo T3x 5G

Rein Version

3

Console Logs / Error Messages

Screenshots / Recordings

No response

Checklist

• I have searched for existing issues to avoid duplicates