Fixed race condition in batch_predict()

[ChaitanyaChute]

Fixes Issue #82

Summary

Fixes a race condition where concurrent batch_predict() requests overwrite the same temp_batch_predict.csv file.

• Generate unique temp filenames using uuid4()
• Add cleanup in a finally block to prevent leftover temp files

Problem

In app/routes/session.py:165, all POST /batch_predict requests write to:

temp_batch_predict.csv

Concurrent requests overwrite each other's data, causing incorrect or corrupted predictions.

Changes

• Added import uuid
• Changed temp filename to:

temp_batch_predict_{uuid4}.csv

• Wrapped logic in try/finally to ensure temp file cleanup