refactor: convert ModerationService and PruneService from classes to singleton objects

- Convert ModerationService class to moderationService singleton
- Convert PruneService class to pruneService singleton
- Update all command files to use new singleton imports
- Update web routes to use new singleton imports
- Update tests for singleton pattern
- Remove getNextCaseId from tests (now private module function)

bot/commands/admin/clearwarning.ts

@@ -1,6 +1,6 @@
 import { createCommand } from "@shared/lib/utils";
 import { SlashCommandBuilder, PermissionFlagsBits, MessageFlags } from "discord.js";
-import { ModerationService } from "@shared/modules/moderation/moderation.service";
+import { moderationService } from "@shared/modules/moderation/moderation.service";
 import { getClearSuccessEmbed, getModerationErrorEmbed } from "@/modules/moderation/moderation.view";
 
 export const clearwarning = createCommand({
@@ -38,7 +38,7 @@ export const clearwarning = createCommand({
             }
 
             // Check if case exists and is active
-            const existingCase = await ModerationService.getCaseById(caseId);
+            const existingCase = await moderationService.getCaseById(caseId);
 
             if (!existingCase) {
                 await interaction.editReply({
@@ -62,7 +62,7 @@ export const clearwarning = createCommand({
             }
 
             // Clear the warning
-            await ModerationService.clearCase({
+            await moderationService.clearCase({
                 caseId,
                 clearedBy: interaction.user.id,
                 clearedByName: interaction.user.username,