Add virtual function detection and annotation to NIC table

[Copilot]

• Understand the codebase structure and NIC data collection
• Modify the NIC info script to detect virtual functions (check for physfn symlink)
• Add a field to nicInfo struct to track if interface is virtual
• Update parseNicInfo function to parse virtual function indicator
• Update nicTableValues to annotate virtual interfaces with "(virtual)"
• Add tests for virtual function detection
• Add test for table output with virtual function annotation
• Verify code quality (format, vet, build)
• Run security checks (CodeQL)
• Address code review feedback: Replace HasPrefix + TrimPrefix with CutPrefix

Summary

Successfully implemented virtual function detection for the NIC table. Virtual functions are now identified by checking for the physfn symlink in sysfs and are annotated with "(virtual)" in the interface name column.

Changes Made:

• Modified NIC info script to detect VFs via /sys/class/net/<ifc>/device/physfn
• Added IsVirtual field to nicInfo struct
• Updated parsing to handle "Virtual Function: yes/no" output using modern CutPrefix idiom
• Modified table rendering to append "(virtual)" to VF interface names
• Added comprehensive test coverage

Example Output:

Name              | Vendor (ID)        | Model
------------------|--------------------|---------------------------------
eth0 (virtual)    | Intel Corporation  | Ethernet Adaptive Virtual Function
eth1              | Intel Corporation  | Ethernet Controller E810-C

Validation:

• ✅ All tests passing (173 lines added)
• ✅ Code formatted with gofmt
• ✅ Passed go vet checks
• ✅ Binary builds successfully
• ✅ No security vulnerabilities (CodeQL)
• ✅ Code follows modern Go idioms (CutPrefix)

Security Summary

No security vulnerabilities were discovered during implementation. CodeQL analysis returned 0 alerts.

Original prompt

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This section details on the original issue you should resolve

<issue_title>Add section for NIC virtual functions</issue_title>
<issue_description>Virtual Functions

Bus	Name	Associated interface
0000:c0:11.0	Ethernet Adaptive Virtual Function	eth0
0000:c0:11.1	Ethernet Adaptive Virtual Function	eth0
0000:c0:11.2	Ethernet Adaptive Virtual Function	eth0

I see two ways it could be done:

By checking the memory mapping under lshw -c network
physical interfaces on a card share the same iomemory regions (always?), and the bus address start
virtual interfaces use memory regions from physical card's memory space
Using files under /sys/bus/pci/devices in a manner similar to this script https://github.com/OpenVisualCloud/Media-Transport-Library/blob/main/script/nicctl.sh (BSD-3-Clause)

Split from this original Issue: #377

</issue_description>

<agent_instructions>Do not create a new table. Extend NIC table to include virtual functions, if not already included. Identify virtual functions by annotating the interface name with "(virtual)". </agent_instructions>

Comments on the Issue (you are @copilot in this section)

Fixes #523

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[harp-intel]

@copilot go-modernize is failing. Replace HasPrefix + TrimPrefix with CutPrefix.

[Copilot]

Fixed in commit c8f9d57. Replaced HasPrefix + TrimPrefix with CutPrefix for the virtual function detection logic.