.NET: Update GitHub.Copilot.SDK to 1.0.0-beta.2 to address NU1903

[Copilot]

Motivation and Context

GitHub.Copilot.SDK 0.1.29 transitively pulls Nerdbank.MessagePack 1.0.2 (via StreamJsonRpc), which has a known high severity vulnerability (GHSA-2cwq-pwfr-wcw3 — attacker-controlled stackalloc in DateTime decoding causes a process-terminating StackOverflowException, fixed in 1.1.62). This surfaces as NU1903 errors and breaks the build under TreatWarningsAsErrors.

Per review feedback, since we don't depend on Nerdbank.MessagePack directly, the cleaner fix is to upgrade GitHub.Copilot.SDK itself rather than pin the transitive dependency — the newer SDK releases (1.0.0-beta.1/1.0.0-beta.2) no longer reference StreamJsonRpc/Nerdbank.MessagePack at all.

Description

• Bumped GitHub.Copilot.SDK from 0.1.29 to the latest 1.0.0-beta.2 in dotnet/Directory.Packages.props. Its only dependencies are now Microsoft.Extensions.AI.Abstractions, Microsoft.Extensions.Logging.Abstractions, and System.Text.Json, eliminating the vulnerable chain.
• Adapted call sites in Microsoft.Agents.AI.GitHub.Copilot, the Agent_With_GitHubCopilot sample, and the unit/integration tests to match the new SDK API:
  • UserMessageDataAttachmentsItem / UserMessageDataAttachmentsItemFile → UserMessageAttachmentFile
  • McpLocalServerConfig (stdio) / McpRemoteServerConfig (http) → McpStdioServerConfig / McpHttpServerConfig (the explicit Type discriminator is no longer needed)
  • McpServers dictionary value type changed from object to the new McpServerConfig base type
  • PermissionRequestResult.Kind is now strongly typed: string → PermissionRequestResultKind enum (Approved / Rejected)

Verified dotnet build succeeds with 0 warnings/errors across net8.0/net9.0/net10.0 for the src project, unit tests, integration tests, and the sample. All 45 unit tests pass.

Note: there is overlap with #5699 which performs the same SDK upgrade; either PR can supersede the other.

Contribution Checklist

• The code builds clean without any errors or warnings
• The PR follows the Contribution Guidelines
• All unit tests pass, and I have added new tests where possible
• Is this a breaking change? If yes, add "[BREAKING]" prefix to the title of the PR.

[Copilot]

Pull request overview

Pins a vulnerable transitive dependency (Nerdbank.MessagePack) via .NET Central Package Management to eliminate NU1903 failures caused by GitHub.Copilot.SDK’s transitive dependency graph.

Changes:

• Adds a central transitive pin for Nerdbank.MessagePack to version 1.1.62 in dotnet/Directory.Packages.props.
• Documents the security motivation inline (GHSA-2cwq-pwfr-wcw3 / NU1903).

[Jacob Alber (lokitoth)]

We don't rely directly on Nerdbank.MessagePack, we get it through the GitHub.Copilot.SDK; should we just update that dependency instead (since the later ones, 1.0.0-beta.1 and 1.0.0-beta.2 don't include the transitive dependency that pulled this in: StreamJsonRpc)? (PR here)

(Happy to do it either way, so approving now, but wanted to raise awareness)

[Jacob Alber (lokitoth)]

(Sorry, wrong tab; did not mean to trigger merge queue)

[Roger Barreto (rogerbarreto)]

Copilot Please follow suggestion from Jacob Alber (@lokitoth), please check most recent version from the SDK

We don't rely directly on Nerdbank.MessagePack, we get it through the GitHub.Copilot.SDK; should we just update that dependency instead

[Copilot]

Copilot Please follow suggestion from Jacob Alber (@lokitoth), please check most recent version from the SDK

We don't rely directly on Nerdbank.MessagePack, we get it through the GitHub.Copilo...

Done in cf5b467 — upgraded GitHub.Copilot.SDK to the latest 1.0.0-beta.2 (which no longer pulls in StreamJsonRpc / Nerdbank.MessagePack) and removed the transitive pin. Adapted call sites to the new SDK API (UserMessageAttachmentFile, McpStdioServerConfig/McpHttpServerConfig, Dictionary<string, McpServerConfig>, PermissionRequestResultKind enum). Builds clean on net8/9/10 and all 45 unit tests pass.

We don't rely directly on Nerdbank.MessagePack, we get it through the GitHub.Copilot.SDK; should we just update that dependency instead (since the later ones, 1.0.0-beta.1 and 1.0.0-beta.2 don...

Switched approach in cf5b467 to upgrade GitHub.Copilot.SDK to 1.0.0-beta.2 instead of pinning the transitive — drops the Nerdbank.MessagePack/StreamJsonRpc chain entirely. (Note: there is overlap with #5699; happy to defer if that one merges first.)

[Roger Barreto (rogerbarreto)]

Superseded by

• .NET: feat: Update Github Copilot SDK to 1.0.0-beta.2 #5699