fix(network): show WiFi connection progress

[NihilDigit]

Description

When starting a WiFi connection through the DMS network backend, the UI did not immediately show which network was being connected. This made slow or failed connection attempts look like the network list had stopped responding, especially when switching from the current network to a saved network with outdated credentials.

This updates the DMS network service to expose isConnecting and connectingSSID as soon as a WiFi connection request starts. The Control Center network detail and Settings WiFi lists now show a row-level Connecting... state with a spinner, disable duplicate connection attempts while another WiFi connection is in progress, and keep the connected network visually distinct from the network being attempted.

Type of change

• Bug fix (non-breaking change that fixes an issue)
• New feature (non-breaking change that adds functionality)
• Breaking change (fix or feature that changes existing behavior)
• Refactor / internal cleanup
• Documentation
• Other

Related issues

None

Screenshots / video

Checklist

• My code follows the conventions in CONTRIBUTING.md
• I have tested my changes locally
• New user-facing strings are wrapped in I18n.tr() with translator context, reusing existing terms where possible
• Go changes: ran make fmt, added/updated tests, make test passes, and go mod tidy is clean
• QML changes: ran make lint-qml with no new warnings
• I have opened a corresponding pull request in dlx-docs to document any new behaviors: https://github.com/AvengeMedia/DankLinux-Docs