Upgrade Squad sample Copilot/MAF dependency chain

[tamirdresher]

Closes #1496

Summary

• bump the Squad sample's GitHub.Copilot.SDK pin from 1.0.3 to 1.0.8
• bump Squad.Agents.AI from 0.5.1-preview.16 to 0.5.6-preview.23
• add an explicit Microsoft.Agents.AI.GitHub.Copilot 1.15.0-rc1 reference for the sample ApiApp
• keep the MAF/Copilot SDK bridge on a single validated version and avoid duplicate SDK target imports
• add and polish a C# AppHost smoke test so CI exercises the real sample startup path
• harden /ask so the sample accepts either prompt or prompts payloads and returns a clean 400 for empty input

Why

CommunityToolkit.Aspire.Hosting.Squad is the canonical upstream home of this Aspire integration. The old blocked SDK-only bump (see bradygaster/squad#1449, and the direct Dependabot follow-ups here such as #1463/#1472/#1477) failed because newer Copilot SDK builds split CopilotClient into a separate assembly while the published MAF adapter still defaulted its buildTransitive import to an older SDK path.

This PR upgrades the sample's full Squad/MAF/Copilot stack together instead of only bumping the direct SDK pin.

PR Checklist

• Created a feature/dev branch in the fork
• Based off latest main branch of toolkit
• PR doesn't include merge commits
• Tests for the changes have been added
• Contains NO breaking changes
• Code follows all style conventions

Validation

• dotnet build .\\examples\\squad\\CommunityToolkit.Aspire.Hosting.Squad.AppHost\\CommunityToolkit.Aspire.Hosting.Squad.AppHost.csproj -c Release
• dotnet build .\\tests\\CommunityToolkit.Aspire.Hosting.Squad.Tests\\CommunityToolkit.Aspire.Hosting.Squad.Tests.csproj -c Release
• full CommunityToolkit.Aspire.Hosting.Squad.Tests suite passed twice locally after the final polish changes
• dotnet list .\\examples\\squad\\CommunityToolkit.Aspire.Hosting.Squad.ApiApp\\CommunityToolkit.Aspire.Hosting.Squad.ApiApp.csproj package --include-transitive
• smoke-tested the sample AppHost manually: /, /swagger/v1/swagger.json, and /ask?squad=dev|research all returned live responses

Other information

• CLA check passes
• no changelog/release-notes file requirement was found in CONTRIBUTING.md or .github
• publish-azure-artifacts and run-tests / noop are expected skipped checks for this PR

[github-actions]

🚀 Dogfood this PR with:

⚠️ WARNING: Do not do this without first carefully reviewing the code of this PR to satisfy yourself it is safe.

curl -fsSL https://raw.githubusercontent.com/CommunityToolkit/Aspire/main/eng/scripts/dogfood-pr.sh | bash -s -- 1485

Or

• Run remotely in PowerShell:

iex "& { $(irm https://raw.githubusercontent.com/CommunityToolkit/Aspire/main/eng/scripts/dogfood-pr.ps1) } 1485"

[Copilot]

Pull request overview

This PR upgrades the Squad sample’s Copilot/MAF dependency chain so the sample’s MAF adapter and GitHub.Copilot.SDK resolve consistently, avoiding mismatched Copilot SDK artifacts after the SDK’s split of CopilotClient into a separate assembly.

Changes:

• Pin GitHub.Copilot.SDK centrally to 1.0.8 and bump Squad.Agents.AI to 0.5.6-preview.23.
• Add an explicit Microsoft.Agents.AI.GitHub.Copilot reference to the Squad sample ApiApp.
• Add an ApiApp property to steer the MAF buildTransitive bridge to the intended Copilot SDK version, and exclude SDK build assets to avoid duplicate target imports.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
examples/squad/CommunityToolkit.Aspire.Hosting.Squad.ApiApp/CommunityToolkit.Aspire.Hosting.Squad.ApiApp.csproj	Pins the sample’s Copilot/MAF package set and forces the MAF bridge onto the intended Copilot SDK version.
Directory.Packages.props	Updates central package pins for the Squad sample’s Copilot SDK and agent adapter dependencies.

[aaronpowell]

got a merge conflict blocking

[tamirdresher]

@copilot please fix the merge conflicts in this pull request.

[aaronpowell]

Copilot says noooooooooooooooo 🤣