MidnightNameplates 0.11.4.2
Blizzard Minion Source Detection Fix

ROOT CAUSE
The friendly pet/minion sub-category is subordinate to Blizzard's master
friendly-nameplate source. 11.4.1 enabled the sub-category CVars but could
leave the master source disabled, so Blizzard never created a nameplate# token.

FIX
- When Midnight needs friendly summons, it requests nameplateShowFriends.
- It also requests the relevant friendly pet/guardian/totem sub-CVars.
- Enemy summons similarly request the enemy master source.
- CVAR_UPDATE is watched so Blizzard Settings cannot silently undo the source.
- Midnight still suppresses Blizzard visuals after the base plate exists.
- Original CVar values are remembered for restoration when source management is disabled.

TEST
1. WoW Options: Friendly Player Nameplates -> Minions OFF.
2. Reload.
3. Midnight -> Summons:
   Enable summoned-unit controls = ON
   Manage Blizzard minion nameplate sources = ON
   Friendly Pet / Minion = ON
4. Bruufenn should acquire a Midnight custom plate.
5. Blizzard's Minions checkbox may become enabled because Midnight needs that source.
6. There must not be a second/blank Blizzard visual plate.
7. Disable Friendly Pet / Minion and verify the summon plate disappears.
8. Friendly player behavior must remain controlled by Midnight's Friendly Player settings.
9. No Lua, taint, protected-action, or secret-value errors.
