refactor: extract Discord.js code from shared services into bot layer

Move terminal.service.ts and prune.service.ts entirely to bot/modules/
since they are Discord-specific. Split lootdrop.service.ts: pure logic
(activity tracking, DB ops, claim) stays in shared/, Discord operations
(message sending, channel interactions) move to bot/modules/economy/
lootdrop.handler.ts. Move effect registry/handlers/types from bot/ to
shared/modules/inventory/ since they contain no Discord.js imports and
are needed by inventory.service.ts in shared.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

bot/events/messageCreate.ts

@@ -15,7 +15,7 @@ const event: Event<Events.MessageCreate> = {
         levelingService.processChatXp(message.author.id);
 
         // Activity Tracking for Lootdrops
-        import("@shared/modules/economy/lootdrop.service").then(m => m.lootdropService.processMessage(message));
+        import("@modules/economy/lootdrop.handler").then(m => m.processLootdropMessage(message));
     },
 };