MidnightNameplates 0.10.1.1 - Profile Delete Fix

ROOT CAUSE
- Deleting the active profile removed it, then ApplyProfile("Default") called
  SaveActiveProfile() first.
- SaveActiveProfile() recreated the just-deleted active profile.
- Result: the profile appeared impossible to delete.

FIX
- Active profile deletion now switches to Default without saving/recreating the deleted profile.
- Character/context references to the deleted profile are reset to Default.
- lastManualProfile is reset if needed.
- Default remains protected.
- Profiles page now shows delete success/failure feedback.

TEST
1. Create Test.
2. Switch to Test.
3. Press DELETE ACTIVE.
4. Test should disappear and Default should become active.
5. /reload: Test must still be gone.
6. Try deleting Default: it should refuse with a message.
7. Delete a non-active copied profile.
8. Context/per-character mappings should fall back to Default.
