Raid tools hide without assist

[RedAces]

What does this PR do?

Hide the new raid tools panel if youre in a raid and dont have assist and are not the raid lead

How was it tested?

Tested on 12.0.7 retail.
NOT tested on 12.1 PTR

Checklist

• New settings default OFF (no behavior change without opt-in)
• Zero cost while disabled: no events registered, no polling, no hooks doing work, no frames built
• Cheap while enabled: event-driven (no polling, no timer-based logic, no per-frame allocations)
• No writes onto Blizzard-owned frames (weak-table pattern used); HookScript/hooksecurefunc only, never SetScript on Blizzard frames
• Tested in-game, works on live retail; no load errors on the 12.1 PTR client