BarEnergy

# BarEnergy 1.0.1 - TBC Anniversary 2.5.6 compatibility

Patch 2.5.6 (and Classic Era 1.15.9) removed several global API functions as part
of the backported "Midnight" UI. This broke BarEnergy on load: it errored during
login before its slash commands were registered, so the bar never appeared and
/be did nothing.

## Fixed
- **Fatal login crash** - `GetCVar` was removed from the global namespace. It is
  called during PLAYER_LOGIN (for pixel-perfect scaling), so its removal aborted
  the whole login handler. Now falls back to `C_CVar.GetCVar`.
- **Energy ticker in combat** - the tick/proc filter used
  `CombatLogGetCurrentEventInfo`, also removed. Now falls back to
  `C_CombatLog.GetCurrentEventInfo`.
- **Warrior Execute detection** - `IsPlayerSpell` / `IsSpellKnown` removed; now
  uses `C_SpellBook.IsSpellKnown`.
- **Aura scanning** - `UnitAura` removed; now falls back to
  `C_UnitAuras.GetAuraDataByIndex`.
- **Options panel** - the removed `InterfaceOptions_AddCategory` (still called by
  the bundled AceConfigDialog) is now shimmed onto the modern Settings API, with a
  standalone config window fallback for `/be gui` if registration fails.
- **Default power colors** - guarded against `PowerBarColor` being unavailable at
  file load.

## Hardened
- Slash commands (`/be`, `/barenergy`) are now registered as the very first action
  in PLAYER_LOGIN, so no future load error can silently disable them.
- The rest of initialization runs inside a protected call; any error is printed to
  chat as `[BE] ERREUR init: ...` instead of failing silently.
- Windowed-resolution parsing is guarded against unexpected CVar formats.

## TOC
- Interface bumped to **20506** (TBC Anniversary / BCC) and **11509** (Classic Era).

No gameplay or configuration changes - energy ticker, tick window, heartbeat sound,
5-second-rule mana tracking and all settings behave exactly as before.