[Feature]: Detect ElvUI loot conflict and offer to disable

[Xerrion]

Problem

When both ElvUI and DragonLoot are installed, ElvUI's loot window (E.private.general.loot) and/or group-loot roll frames (E.private.general.lootRoll) hook the same Blizzard frames DragonLoot replaces. Users see both addons' UIs show up, or get inconsistent behavior depending on which hooks run last.

Proposed Solution

On OnEnable, detect whether ElvUI is loaded AND has either loot toggle enabled AND DragonLoot's matching feature (lootWindow.enabled / rollFrame.enabled) is also enabled. If so, show a StaticPopup offering to disable the ElvUI modules and ReloadUI(). Respect the user's decision - remember dismissal per-profile, scoped by the exact conflict signature so re-enabling an ElvUI feature later re-prompts.

Alternatives

• Silently disable ElvUI's modules - rejected: never mutate another addon's config without consent.
• Disable DragonLoot's features instead - rejected: the user installed DragonLoot to use it.
• Disable the whole ElvUI addon - rejected: nukes unrelated ElvUI features the user wants.

Notes

ElvUI's M:LoadLoot / M:LoadLootRoll gates are only checked at ElvUI's Initialize phase, so a ReloadUI() is required for the flags to take effect. AceDB persists E.private to ElvPrivateDB on logout automatically - no direct SV mutation needed.