MidnightNameplates 0.11.0.4 - Visibility Enforcement + Stacking Control

FIX 1 - VISIBILITY ENFORCEMENT
- Unit Type enabled/disabled state is now authoritative.
- Classification enabled/disabled state is now authoritative.
- Rules, Intelligence, Target, Threat, Casts and Auras cannot resurrect a disabled plate.
- World-object/mailbox filter still runs first.
- Disabled custom plates are hidden before styling.

TEST VISIBILITY
1. Disable Elite -> Elite plates must disappear.
2. Re-enable Elite -> Elite plates return.
3. Repeat for Rare / Rare Elite / Boss / Normal where available.
4. Disable Friendly Player -> friendly player custom plates disappear.
5. Disable Friendly NPC / Enemy Player / Enemy NPC and verify.
6. Targeting a disabled unit must not bring the Midnight plate back.

FIX 2 - STACKING / OVERLAP
General -> Nameplate Stacking:
- STACKING mode
- OVERLAP mode
- Vertical overlap spacing
- Horizontal overlap spacing

Implementation uses Blizzard nameplate CVars:
- nameplateMotion
- nameplateOverlapV
- nameplateOverlapH

TEST STACKING
1. Use a crowded pack like the Wind Serpent screenshot.
2. Set STACKING.
3. Increase Vertical overlap spacing until aura rows no longer collide.
4. Verify plates separate rather than draw directly on top of each other.
5. Try OVERLAP mode and confirm the difference.
6. Friendly-player auras remain working.
7. No Lua/taint/secret-value errors.
