[/find plugin] External integrations: WorldEdit/FAWE shop cleanup + WorldGuard region placeholder

Part of PAR-166 (spin out /find). Plugin/presentation — new spun-out repo; filed under ChestShop until that project exists.

Port the legacy chestshop-database adapter modules:

• WorldEdit + FastAsyncWorldEdit (FAWE): when a WE/FAWE operation removes shop blocks, deactivate the affected shops in the registry (call MarketApi.deactivateShop). Legacy: adapters/worldedit, adapters/fawe (WorldEditHandler/FAWEHandler + loggers). Without this, bulk-removed shops linger as active=1 ghosts in chestshop_shop.
• WorldGuard: expose a %region-name% placeholder for use in shop display/preview templates. Legacy: adapters/worldguard/WorldGuardHandler.
• (Optional) Geyser/Floodgate Bedrock detector if the holograms/GUI need per-platform handling — legacy ships adapters/geyser-floodgate; include only if the GUI requires it.

Soft dependencies (plugin present-or-not), mirroring the legacy adapter pattern.