Add Animations feature + fix own-pet tooltip false positive

Animations (all optional, default on, per-effect toggles):
- New Options -> Animations tab with master switch + per-effect checkboxes
- Embed PizzaSauce animation library (api/PizzaSauce.lua)
- fx-celebrate: firework + banner when a pet learns a new ability/rank,
  triggered from core-scan-beasttraining pet-learn hook
- Hunter's Book: slide + fade on open, results list fade on tab switch
- Options window: slide + fade on open
- All new user-facing strings keyed (ANIM_* namespace)

Fixes:
- Tooltip #19: own-pet lines (mood/loyalty/happiness/XP) no longer
  misfire on party members / targets. Removed the fragile title-name
  fallback in MTH_TT_IsTooltipOnOwnPet; ownership now requires positive
  unit identity.

Temp (remove before release): /mth fx and /mth fxdebug diagnostics.

api/options-tree.lua

@@ -52,6 +52,7 @@ MTH_OPTIONS_TABS = MTH_OPTIONS_TABS or {
 	{ key = "ChronometerClassSpells", label = "Hunter Spells", frame = "MetaHuntOptionsChronometer" },
 	{ key = "ChronometerClassEvents", label = "Hunter Events", frame = "MetaHuntOptionsChronometer" },
 	{ key = "ChronometerRacial", label = "Racial", frame = "MetaHuntOptionsChronometer" },
+	{ key = "Animations", label = "Animations", frame = "MetaHuntOptionsAnimations" },
 	{ key = "Credits", label = "Credits", frame = "MetaHuntOptionsCredits" },
 }
 
@@ -92,6 +93,7 @@ MTH_OPTIONS_TREE = MTH_OPTIONS_TREE or {
 			{ label = "Racial", key = "ChronometerRacial" },
 		},
 	},
+	{ label = "Animations", key = "Animations" },
 	{ label = "Credits", key = "Credits" },
 }