docs: add JSDoc to service public methods

One-line JSDoc on 82 methods across 11 service files for quick
scanning without reading full implementations.

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

shared/modules/economy/lootdrop.service.ts

@@ -213,12 +213,20 @@ async function clearCaches() {
 }
 
 export const lootdropService = {
+    /** Delete expired lootdrops from the database; optionally includes already-claimed ones. */
     cleanupExpiredLootdrops,
+    /** Record a message in a channel and return whether a lootdrop should spawn based on activity and RNG. */
     trackActivity,
+    /** Calculate a random lootdrop reward amount and currency, with optional overrides. */
     calculateReward,
+    /** Save a spawned lootdrop to the database with a 10-minute expiration. */
     persistLootdrop,
+    /** Remove a lootdrop by message ID and return its channel ID for Discord cleanup. */
     removeLootdrop,
+    /** Atomically claim a lootdrop for a user; credits reward to their balance. */
     tryClaim,
+    /** Get current lootdrop system state including the most active channel and spawn config. */
     getLootdropState,
+    /** Clear all in-memory activity tracking and cooldown caches. */
     clearCaches,
 };