GeezerVison

Backport of #28326 to release/v7.6.10

Triggered by Dongbo Wang (@daxian-dbw) on behalf of Aditya Patwardhan (@adityapatwardhan)

Original CL Label: CL-BuildPackaging

/cc @PowerShell/powershell-maintainers

Impact

REQUIRED: Choose either Tooling Impact or Customer Impact (or both). At least one checkbox must be selected.

Tooling Impact

• Required tooling change
• Optional tooling change (include reasoning)

Enables release builds to consume bundled PowerShell modules from the internal early-access module feed independently of the selected .NET feed. UseEarlyAccessModules defaults to false, preserving existing feed selection unless explicitly enabled.

Customer Impact

• Customer reported
• Found internally

Regression

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• Yes
• No

This is not a regression.

Testing

Original PR adds test/infrastructure/NugetConfig.Tests.ps1 covering module-feed selection across source modes, authentication combinations, module-only authentication without a .NET feed selector, and token-acquisition failures. The backport cherry-picked without conflicts and the worktree is clean. Local tests were not run; backport CI validation is required before merge.

Risk

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• High
• Medium
• Low

Changes shared build pipeline and feed-authentication infrastructure. The capability is opt-in via UseEarlyAccessModules, which defaults to false, preserving existing feed behavior. Included infrastructure tests cover feed selection and authentication scenarios; backport CI must pass before merge.