Add a short FAQ entry explaining gates vs sandboxing

[rxdt]

Goal

Add a short FAQ entry explaining the difference between LoopGate gates and real sandboxing.

Suggested scope

Clarify that gates decide what lands in commits, but they are not a full OS sandbox.

Acceptance criteria

• Add one concise FAQ-style section or bullet.
• Do not weaken the existing safety warning.
• Docs-only PR.

[gargi-gif]

Hi! I would love to pick this up. I saw the existing safety warnings in README.md. My plan is to add the clarification about gates vs. sandboxes right there so it doesn't weaken the original warning. Does README.md sound like the right place for this, or is there a dedicated FAQ document in the repo you'd prefer me to use? Let me know if I can get this assigned to me!

[rxdt]

That sounds like a great spot in README.md!