Extend exclude assets feature to non-codeflow subscriptions

[Copilot]

This PR extends the excluded assets feature to work with non-codeflow (regular dependency-only) subscriptions, addressing the requirement that repos should be able to exclude specific packages like arcade while still receiving other dependency updates.

Changes Made

Core Implementation:

• Modified PullRequestUpdater.GetRequiredUpdates() to fetch subscription data and filter out excluded assets before processing dependencies
• Added helper methods GetExcludedAssetsMatcher() and IsExcludedAsset() that use the same filtering pattern as the existing VMR codeflow implementation
• Assets matching excluded patterns are now filtered from build.Assets before calling GetRequiredNonCoherencyUpdates()

Documentation and UI:

• Updated popup help text in AddSubscriptionPopUp.cs and UpdateSubscriptionPopUp.cs to remove the "source-enabled subscriptions (VMR code flow)" restriction
• Updated property documentation on Subscription.ExcludedAssets to indicate it works for all dependency updates

How It Works

When a subscription update is triggered:

1. GetRequiredUpdates() fetches the subscription from the database (including ExcludedAssets)
2. Creates a Matcher from the excluded asset patterns using GetExcludedAssetsMatcher()
3. Filters the build assets using IsExcludedAsset() before processing dependencies
4. The filtered assets are passed to dependency resolution, effectively excluding them from updates

Example Use Case

A non-VMR repo can now create a subscription that takes the latest VMR build but excludes arcade packages:

Excluded assets: Microsoft.DotNet.Arcade.*

This allows the repo to receive all other dependency updates while staying on .NET N-1 arcade.

Testing

• Verified existing UpdateAssetsTests pass (10 tests passing) to ensure no regression
• Confirmed DARC CLI and DependencyFlow components build successfully
• Implementation follows the same filtering pattern as existing VMR codeflow excluded assets feature

Fixes #4806.

---

💡 You can make Copilot smarter by setting up custom instructions, customizing its development environment and configuring Model Context Protocol (MCP) servers. Learn more Copilot coding agent tips in the docs.

[premun]

Please add tests in the existing ProductConstructionService.DependencyFlow.Tests project for the PullRequestUpdater that would cover updates where either some or even all packages are excluded.

[Copilot]

Please add tests in the existing ProductConstructionService.DependencyFlow.Tests project for the PullRequestUpdater that would cover updates where either some or even all packages are excluded.

Added comprehensive tests in the existing ProductConstructionService.DependencyFlow.Tests project for the PullRequestUpdater that cover updates where either some or all packages are excluded. The tests verify that excluded assets are properly filtered out before being passed to dependency resolution. Changes committed in 0f73782.

[premun]

Seems like there are still some ties between excluded assets being only utilized for source-enabled subscriptions. For example in UxHelpers.cs.

Can you search all usages of ExcludedAssets and whether we can decouple so that it is valid in non-source-enabled subscriptions?

[Copilot]

Seems like there are still some ties between excluded assets being only utilized for source-enabled subscriptions. For example in UxHelpers.cs.

Can you search all usages of ExcludedAssets and w...

Found and removed all remaining restrictions that tied excluded assets to source-enabled subscriptions. Removed validation checks in SubscriptionPopUp.cs, AddSubscriptionOperation.cs, and UpdateSubscriptionOperation.cs, and updated UxHelpers.cs to display excluded assets for all subscriptions. Changes committed in a9682a4.