Can't select the port forward entry

**Describe the issue**
Trying to modify an existing port forward setting
- Edit selected VM
- In the left panel of the dialog, select "Port Forward" under "Network"(when Network Mode is "Emulated VLAN")
- Existing port forward settings shown on the right, but can't be selected by clicking it

**Configuration**
* UTM Version: 5.0.1
* macOS Version: Tahoo 26.2
* Mac Chip (Intel, M1, ...): M3Max

Reproduce the issue in UTM 5.0.1 by editing a VM, opening Network > Port Forward with Network Mode set to Emulated VLAN, and trying to select the existing entry. Trace the port-forward settings UI from there; done means an existing port-forward entry can be selected for modification.

Written by the indexing model from the issue text.