Restore remaining files deleted by force-full sync

[Brandon Miller (brandom-msft)]

Context

Force-full sync commit 1a7f828fd60e6b0f14549612cf25e7bf2c906931 replaced the public tree with the private export and deleted public content that should have survived the recovery. PR 912 restored the required trusted validation lane; this PR restores the remaining accidental deletions.

What changed

• Restore 55 files across 11 customer-facing C# Foundry Local sample directories.
• Restore 11 public-only validation pilot/reporting files, including the daily validation workflow, report consumer, discovery/runtime scripts, focused tests, and self-test workflow.
• Add the two missing central package versions required by the restored samples' Linux GPU references.
• Make restored sample build commands target their single .csproj explicitly instead of auto-selecting .sln files with ARM64 defaults on Linux.
• Preserve every addition and modification delivered by the force-full sync.

All 66 restored index blobs initially matched rollback point 328833f9d39e8e0a80975950cc98dc00d9c63aff. The 55 Foundry Local files also matched current microsoft-foundry/foundry-samples-pr main; only the 11 sample.yaml build commands were subsequently narrowed to explicit project targets to satisfy public validation.

Why restore all remaining deletions

• The Foundry Local samples are still present on current private main, remain CODEOWNERS-routed to the Foundry Local team, and are referenced by public Microsoft Learn content.
• The validation pilot/report stack was actively updated through August 12 and backs the in-progress declared live-service validation workstream. PR 912 left it deleted only to keep that emergency fix scoped to the required trusted check; it did not deprecate the stack.
• No remaining deletion from the force-full commit had evidence of intentional removal.

CI follow-up

The first PR run exposed a latent central package management defect shared by all restored C# projects: Microsoft.ML.OnnxRuntime.Gpu and Microsoft.ML.OnnxRuntimeGenAI.Cuda had versionless PackageReference entries but no matching PackageVersion entries. The follow-up pins them to 1.26.0 and 0.14.1, respectively—the dependency versions recorded by the Foundry Local v1.2.1 release used by these samples.

The next run cleared package restore and exposed a second latent issue: dotnet build without an explicit target auto-selected each restored solution, whose default ARM64 configuration conflicts with the Linux runner's linux-x64 runtime. Each manifest now restores and builds its one .csproj explicitly; the solution files remain available for users and Microsoft Learn references.

Validation

• Validation pilot unit tests: 12 passed.
• Validation report unit tests: 6 passed.
• Sample discovery acceptance tests: 23 passed.
• Restored Python scripts compile successfully.
• All three restored workflow files parse successfully as YAML.
• All 13 current C# Foundry Local sample.yaml manifests parse and contain required metadata.
• All 11 explicit project commands resolve to exactly one .csproj.
• Workflow structure harness passes on GitHub-hosted runners.
• MSBuild evaluation confirms both new package versions are applied to the restored projects.
• Local package restore is environment-blocked by this machine's TLS handshake with NuGet; GitHub-hosted sample validation is the authoritative build check.

Tracking

• ADO 5449716 — https://msdata.visualstudio.com/Vienna/_workitems/edit/5449716
• ADO 5511477 — https://msdata.visualstudio.com/Vienna/_workitems/edit/5511477