Fix: Remove faulty MaxBodySizeMiddleware

Fix: Increase max request body size to 50MB

Merge branch 'main' of https://github.com/trustdemons05/VoiceDifferentiator

Fix: Add root endpoint for Render health checks

Add /detect-external endpoint for external tester compatibility

Simplify: Flatten API response to classification, confidence, explanation list

Refactor: Clean output and improve confidence logic

Fix syntax errors in routes.py for Render deployment

Cleanup: Remove debug prints, improve logging, and refactor comments