chore(discord-gateway): remove unused imports from response logger

- aiAnalyzer.ts: removed unused logAnalysisSummary and logFalsePositiveDetected
- llmModerationClient.ts: removed unused logVisionAnalysis, logVisionError, logRetryAttempt

These functions are not called in the codebase.

services/discord-gateway/src/modules/ai-moderation/aiAnalyzer.ts

@@ -29,8 +29,6 @@ import { attemptAutoDeleteFlaggedMessage } from "./autoDeleteManager.js";
 import { buildConversationContext } from "./conversationContext.js";
 import { runModerationAnalysis } from "./llmModerationClient.js";
 import {
-  logAnalysisSummary,
-  logFalsePositiveDetected,
   logModerationError,
 } from "./responseLogger.js";