Bug/Feat: Sandbox config to selectively enable tools

Describe the feature or problem you'd like to solve

Feature Request: Sandbox config in settings.json to selectively enable tools, and/or whitelist bundled copilot package tools

Proposed solution

potentially have some tools { ... } within sandbox section in settings.json to enable allowed tools/apps/executables
(or provide documentation on how best to accomplish this if fits somehow in current schema)

more specifically, encountered this around copilot bundled rg ripgrep, while in sandbox enabled:

Search "xunit\.V3" (sandboxed)  sh: 1:~/.copilot/pkg/linux-x64/1.0.75/ripgrep/bin/linux-x64/rg: not found

Search is blocked because the bundled  rg  executable is unavailable under the current sandbox policy.
Please review  /sandbox  and retry.

ideally specifically around this, executable packages that are bundled within distributed copilot are just marked "safe" by default and end user does not need to do anything additional to whitelist to allow these in sandbox mode

Example prompts or workflows

No response

Additional context

No response

Beginne mit dem Lesen der Konfiguration settings.json und des Verhaltens der /sandbox-Richtlinie. Verfolge anschließend, wie die gebündelte ausführbare Datei unter ~/.copilot/pkg/linux-x64/1.0.75/ripgrep/bin/linux-x64/rg geprüft wird. Ermittle, ob das vorhandene Schema erlaubte Tools ausdrücken kann oder ob gebündelte Tools einen sicheren Standardwert benötigen; abgeschlossen ist die Aufgabe, wenn die vorgesehene Konfiguration oder Dokumentation definiert ist und die sandboxed Search rg verwenden kann.