feat: Implement session processing and refresh schedulers

- Added processingScheduler.js and processingScheduler.ts to handle session transcript processing using OpenAI API.
- Implemented a new scheduler (scheduler.js and schedulers.ts) for refreshing sessions every 15 minutes.
- Updated Prisma migrations to add new fields for processed sessions, including questions, sentimentCategory, and summary.
- Created scripts (process_sessions.mjs and process_sessions.ts) for manual processing of unprocessed sessions.
- Enhanced server.js and server.mjs to initialize schedulers on server start.

prisma/schema.prisma

@@ -43,7 +43,8 @@ model Session {
   country             String?
   language            String?
   messagesSent        Int?
-  sentiment           Float?
+  sentiment           Float?   // Original sentiment score (float)
+  sentimentCategory   String?  // "positive", "neutral", "negative" from OpenAPI
   escalated           Boolean?
   forwardedHr         Boolean?
   fullTranscriptUrl   String?
@@ -53,5 +54,8 @@ model Session {
   tokensEur           Float?
   category            String?
   initialMsg          String?
+  processed           Boolean? // Flag for post-processing status
+  questions           String?  // JSON array of questions asked by user
+  summary             String?  // Brief summary of the conversation
   createdAt           DateTime @default(now())
 }