MIDNIGHTNAMEPLATES — PHASE 11.12
BLIZZARD OPTIONS INTEGRATION

ADDED
- MidnightNameplates now registers once under:
  Esc > Options > AddOns > MidnightNameplates
- Blizzard landing page shows addon name/version.
- Open MidnightNameplates button launches the full custom editor.
- /mnp and /midnightnameplates remain unchanged.
- Blizzard Settings is hidden before opening the custom editor so the two
  windows do not obscure each other.

ARCHITECTURE
- Uses WoW 12.1 Settings.RegisterCanvasLayoutCategory.
- Uses Settings.RegisterAddOnCategory.
- Registration happens once after addon initialization.
- The full MidnightNameplates editor remains independent from Blizzard's
  Settings canvas.
- No CVar changes.
- No nameplate runtime changes.
- No polling/tickers added.

TEST
1. /reload.
2. Esc > Options > AddOns.
3. Confirm MidnightNameplates appears alphabetically in the addon list.
4. Click MidnightNameplates.
5. Confirm title/version/description appear.
6. Click Open MidnightNameplates.
7. Blizzard Options closes and the Midnight editor opens.
8. Close editor and use /mnp.
9. /midnightnameplates also opens it.
10. Confirm no duplicate MidnightNameplates entries after another /reload.
11. Test normal nameplates: behavior must match Phase 11.11.
12. No Lua errors.
13. No taint/protected-action errors.
14. No FPS regression.

PASS -> Phase 12.0 RC1 — Release Candidate / Code Freeze.
