Remove dead upstream machinery: ItemBridge + ShowItem integrations + bStats telemetry

Same profile as the bungee removal — inherited upstream machinery serving zero purpose on the democracycraft server. Confirmed against the live plugin list.

ItemBridge integration — a custom-item bridge parallel to Nexo. The ItemBridge plugin isn't installed (Nexo/NexoAddon/NexoBoltAddon is the custom-item stack). Deleted integration/ItemBridge, its ItemService hooks (enableItemBridge, itemBridgeEnabled, the parse/queryString branches), the Dependencies case + enum entry, and the plugin.yml softdepend + compileOnly dep.

ShowItem integration — hover-item display in shop messages. The ShowItem plugin isn't installed. Deleted integration/ShowItemHook, the injections + showItem.sendMessage branches in TransactionService/InfoService (now always plain messages), the Dependencies case + enum, the SHOWITEM_MESSAGE config + config.yml, and the softdepend + compileOnly dep.

bStats telemetry — new Metrics(this, 1109) phoned home to bStats.org under upstream ChestShop's plugin ID, leaking this private fork's config into a public dashboard. Removed the Metrics field/init, startStatistics() (69 lines + 29 charts), createStaticDrilldownStat/getChartArray/getMetrics, the Dependencies charts, the INCLUDE_SETTINGS_IN_METRICS config, and the org.bstats dependency + shade relocation. Kept the local MetricsModule counters + /csmetrics command (no phone-home).

Net −900+ lines across the three. plugin.yml softdepend is now [Treasury, Business, WorldGuard, GriefPrevention, Nexo]. :chestshop:build green; server enables cleanly (no telemetry call); suite 41/42 (known proprietor-settle flake; the Nexo custom-item test passes).