SnDisplayShops v2.0.0

Player-owned display shops: place a tagged item, set a price, and it trades on its own.

What it does

• Shops are placed, not commanded. A shop is any block placed from a tagged item, so its
  material is whatever the operator configures. Identity lives in the item's PDC, never in the
  block type.
• A rotating hologram over every shop. A native ItemDisplay spinning above a text line, with
  DecentHolograms driving the text where it is installed and a native TextDisplay where it is not.
• Two menus. Buyers get a compact offer with a one-click and a trade-all button; owners get a
  full management screen for the item, the price, the currency, the direction, pausing, stock and
  pickup.
• Buy or sell. A shop faces either way: it sells its stock to players, or it buys from them and
  pays out of its owner's balance.
• Storage without slots. Stock is held per item variant as a 64-bit amount rather than as
  inventory slots, so a shop can hold more of something than a chest could ever represent.
• As many currencies as you configure. Each one is independently backed by an economy plugin's
  commands or by EdTools, so a server can run coins, gems and tokens side by side.
• SuperiorSkyblock aware. Shops on an island can be removed with it when it disbands or when
  their owner loses membership, both behind operator toggles.
• PlaceholderAPI: %sndisplayshops_shops_count%, %sndisplayshops_shops_max%,
  %sndisplayshops_shops_total%.
• A public API for other plugins to read shops and their stock, and to draw stock down.

Requirements

• Paper 1.20.x or 1.21.x
• SnLib
• Optional: PlaceholderAPI, DecentHolograms, EdTools, SuperiorSkyblock

Configuration

Everything the plugin says and every number it uses lives in config.yml, lang/messages_en.yml,
guis/buyer.yml and owner-menu.yml. All four are managed: new keys are merged in on upgrade and
your edits are kept.

Two worth knowing before you tune them:

• database.pool-size ships at 1 on purpose. Two writers can land a shop's stock updates out of
  order, and the losing write is the one that survives a restart. The plugin logs a SEVERE if it
  finds MySQL configured above 1.
• limits.max-pickup-stacks has no "off" value. Picking up a shop hands its whole stock back in
  one tick, so an unbounded value is a hang rather than a preference.