feat(windows): add Windows 2025 support for Windows Cilium Networking (WCN)

[rzlink]

/kind feature

What this PR does / why we need it:
This enables Windows 2025 VHDs to download and cache the WCN package (v1.3.0) during VHD build, following the same pattern as Windows 23H2.

Which issue(s) this PR fixes:

Fixes #

Special notes for your reviewer:

Release note:

Add Windows 2025 Cilium Networking (WCN) feature

[Copilot]

Pull request overview

Adds Windows Server 2025 coverage for Windows Cilium Networking (WCN) so VHD build can download/cache the WCN package (mirroring the existing Windows 23H2 behavior), and extends snapshot/e2e scenarios to validate the generated Windows CSE artifacts.

Changes:

• Extend components.json WCN OCI artifact selection to include Windows SKU 2025* (v1.3.0).
• Add new Windows 2025 Gen2 NextGenNetworking snapshot test cases (enabled / enabled-no-config / disabled) and corresponding expected CustomData + CSECommand outputs.
• Add a (currently skipped) e2e scenario for Windows 2025 Gen2 with WCN enabled.

Reviewed changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
parts/common/components.json	Adds windowsSkuMatch: "2025*" for the WCN OCI artifact so Windows 2025 VHD builds cache the package.
pkg/agent/baker_test.go	Adds snapshot test entries for Windows 2025 Gen2 NextGenNetworking variants to validate generated outputs.
pkg/agent/testdata/AKSWindows2025Gen2+NextGenNetworking/CustomData	New expected Windows CSE CustomData output with WCN enabled + config.
pkg/agent/testdata/AKSWindows2025Gen2+NextGenNetworking/CSECommand	New expected CSE command output for the Windows 2025 Gen2 NextGenNetworking case.
pkg/agent/testdata/AKSWindows2025Gen2+NextGenNetworkingNoConfig/CustomData	New expected Windows CSE CustomData output with WCN enabled + empty config.
pkg/agent/testdata/AKSWindows2025Gen2+NextGenNetworkingNoConfig/CSECommand	New expected CSE command output for the “enabled but no config” case.
pkg/agent/testdata/AKSWindows2025Gen2+NextGenNetworkingDisabled/CustomData	New expected Windows CSE CustomData output with WCN disabled.
pkg/agent/testdata/AKSWindows2025Gen2+NextGenNetworkingDisabled/CSECommand	New expected CSE command output for the WCN-disabled case.
e2e/scenario_win_test.go	Adds a skipped e2e scenario wiring NextGenNetworking/WCN on Windows 2025 Gen2 for future enablement.

[timmy-wright]

I'm not sure why we needed the generated data update - it shouldn't be necessary for this PR. But if it was needed, then it was needed.

[github-actions]

Changes cached containers or packages on windows VHDs

Please get a Windows SIG member to approve.

The following dif file shows any additions or deletions from what will be cached on windows VHDs organised by VHD type.

• Additions are new things cached.
• Deletions are things no longer cached.

diff --git a/vhd_files/2025-gen2.txt b/vhd_files/2025-gen2.txt
index fbaa116..7c16091 100644
--- a/vhd_files/2025-gen2.txt
+++ b/vhd_files/2025-gen2.txt
@@ -13,0 +14 @@ c:\akse-cache\csi-proxy\: https://packages.aks.azure.com/csi-proxy/v1.1.2-hotfix
+c:\akse-cache\wcn\: mcr.microsoft.com/wcn/package:1.3.0-cpu-arch
diff --git a/vhd_files/2025.txt b/vhd_files/2025.txt
index 5555b70..a70d58f 100644
--- a/vhd_files/2025.txt
+++ b/vhd_files/2025.txt
@@ -13,0 +14 @@ c:\akse-cache\csi-proxy\: https://packages.aks.azure.com/csi-proxy/v1.1.2-hotfix
+c:\akse-cache\wcn\: mcr.microsoft.com/wcn/package:1.3.0-cpu-arch