MidnightNameplates 0.11.4.7.1
Emergency Syntax Repair

FIXED
- Core/Engine.lua orphaned end inside OnEvent.
- UI/Config.lua malformed Summons page after emergency source-management rollback.
- Rebuilt the complete Summons page.
- Diagnostic button uses CreateTextButton.

SAFETY ROLLBACK PRESERVED
- No summon CVar writes.
- No CVAR_UPDATE registration.
- No automatic summon source ownership.

TEST
1. /reload.
2. No Engine.lua syntax error.
3. /mnp opens.
4. No Config.lua EOF/end error.
5. Startup/reload should not exhibit the CVar-driven FPS hang.
6. Blizzard Minions OFF -> no summon plate expected.
7. Blizzard Minions ON manually -> Midnight can skin exposed summon plates.
8. No Lua / taint / protected-action / secret-value errors.
