Copilot in Visual Studio adds PR context and changes BYOM
GitHub's September Visual Studio update lets the Git agent inspect attached GitHub or Azure DevOps pull requests through MCP, moves bring-your-own-model support to the new Agent preview, and adds an agent action for NuGet Audit warnings. Existing Ollama models must be re-added after the BYOM change.
Why it matters: Pull-request review, private model routing and package remediation now share an agent harness inside Visual Studio. The breaking BYOM path and write-capable dependency fix make model, connector and change authority visible upgrade concerns.