GitHub Copilot app gains local sandboxing and OpenTelemetry

After this week's model additions (Claude Opus 5.5, GPT-6 Sol/Luna, Grok 4.7), GitHub Copilot's changelog adds Release-level local sandboxing for the Copilot app (Sep 23) and OpenTelemetry support (Sep 22), plus faster C++ code intelligence via whole-codebase indexing and JetBrains improvements.