UI: Fix VNF NIC mapping network select always disabled

[Gia-Bursulaia]

Description

Fixes VNF NIC mapping network select dropdown which was permanently disabled in the UI.

Root cause:
In ui/src/views/compute/wizard/VnfNicsSelection.vue the disabled attribute
was written as a plain HTML string instead of a Vue reactive binding (missing : prefix).
In Vue/Ant Design, any non-empty string is treated as truthy, making the select
always disabled regardless of state.

Steps to reproduce:

1. Create an Isolated network (WAN) and L2 network (LAN)
2. Go to Network → VNF Appliances → Add VNF Appliance
3. Select a VNF template with NIC definitions
4. Add networks on the Networks step
5. Proceed to VNF NIC Mappings step — all dropdowns are disabled

Expected: Network dropdowns are enabled and selectable
Actual: All dropdowns permanently disabled, VNF cannot be deployed via UI

Tested on: CloudStack 4.22.1.0, KVM hypervisor

Types of changes

• Bug fix (non-breaking change which fixes an issue)

Feature/Enhancement Scale or Bug Severity

• Minor

[boring-cyborg]

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[bernardodemarco]

@blueorangutan ui

[blueorangutan]

@bernardodemarco a Jenkins job has been kicked to build UI QA env. I'll keep you posted as I make progress.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 3.51%. Comparing base (be51948) to head (0b25837).

❗ There is a different number of reports uploaded between BASE (be51948) and HEAD (0b25837). Click for more details.

HEAD has 1 upload less than BASE

Flag	BASE (be51948)	HEAD (0b25837)
unittests	1	0

Additional details and impacted files

@@              Coverage Diff              @@
##               main   #13359       +/-   ##
=============================================
- Coverage     18.10%    3.51%   -14.60%     
=============================================
  Files          6037      464     -5573     
  Lines        542798    40159   -502639     
  Branches      66457     7560    -58897     
=============================================
- Hits          98298     1413    -96885     
+ Misses       433453    38556   -394897     
+ Partials      11047      190    -10857     

Flag	Coverage Δ
uitests	3.51% <ø> (ø)
unittests	?

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