feat: add repository pattern, service layer architecture, and scheduler management

- Implement repository pattern for data access layer
- Add comprehensive service layer for business logic
- Create scheduler management system with health monitoring
- Add bounded buffer utility for memory management
- Enhance security audit logging with retention policies

lib/importProcessor.ts

@@ -1,5 +1,5 @@
 // SessionImport to Session processor
-import { ProcessingStage, SentimentCategory } from "@prisma/client";
+import { ProcessingStage } from "@prisma/client";
 import cron from "node-cron";
 import { withRetry } from "./database-retry";
 import { getSchedulerConfig } from "./env";
@@ -77,34 +77,6 @@ function parseEuropeanDate(dateStr: string): Date {
   return date;
 }
 
-/**
- * Helper function to parse sentiment from raw string (fallback only)
- */
-function _parseFallbackSentiment(
-  sentimentRaw: string | null
-): SentimentCategory | null {
-  if (!sentimentRaw) return null;
-
-  const sentimentStr = sentimentRaw.toLowerCase();
-  if (sentimentStr.includes("positive")) {
-    return SentimentCategory.POSITIVE;
-  }
-  if (sentimentStr.includes("negative")) {
-    return SentimentCategory.NEGATIVE;
-  }
-  return SentimentCategory.NEUTRAL;
-}
-
-/**
- * Helper function to parse boolean from raw string (fallback only)
- */
-function _parseFallbackBoolean(rawValue: string | null): boolean | null {
-  if (!rawValue) return null;
-  return ["true", "1", "yes", "escalated", "forwarded"].includes(
-    rawValue.toLowerCase()
-  );
-}
-
 /**
  * Parse transcript content into Message records
  */