YetAnotherHealPrediction

Adds heal prediction overlays to Classic Era's default unit and raid/party frames, plus a mana-cost prediction bar. Rebranded from HealPredictionClassic under yet another name and migrated to the 1.15.9 shared codebase API .

Working:
- PlayerFrame, TargetFrame, PetFrame
- Default (non-raid-style) party frames
- Compact/raid-style party frames
- Mana-cost prediction bar
Not working / opt-in with caveats:
- Enabling Nameplate heal prediction can trigger a Blizzard client bug (a UI "taint" error) introduced by nameplate changes in Classic Era patch 1.15.9 - not a bug in heal prediction itself. Opt in via the options panel if you want it; see the checkbox's tooltip for details.
Out of scope (not bugs, or currently no planned):
- Party-pet mini-icon heal prediction
- Real amount-based Power Word: Shield / absorb-shield tracking — this addon has never tracked real shield amounts, and the Blizzard API for it doesn't return usable data on Classic Era
- Heal-absorb glow — the underlying mechanic (effects that reduce/negate incoming healing, like Death Knight Necrotic Strike in later expansions) doesn't currently exist in Classic Era content
- A cosmetic BugSack error that only fires while Blizzard's Edit Mode is open and you hover a mock buff/debuff overlapping a real one — harmless, left as-is on purpose