Fix production errors: add missing case studies file and improve error handling

Fix API URL construction - use relative URLs with Vercel rewrites

Update Vercel rewrites to use Railway backend URL

Fix frontend API configuration for Railway backend

Fix requirements.txt for Railway deployment

Simplify Railway deployment - use auto-detection

Fix Railway Python deployment configuration

Add Railway deployment configuration

Add gunicorn config with 5-minute timeout for Anthropic API calls

Enhance CORS configuration for preflight requests

Fix CORS: Add www subdomain to allowed origins

changed backend url in prod

Merge branch 'main' of https://github.com/lkalajzic/clauderoicalculator

Add vercel.json with bun configuration

Update requirements.txt gunicorn==21.2.0