- Add field_validator to expand literal \n in PEM keys (auth config + shared config)
- Set extra='ignore' on shared Settings so service-specific .env vars don't cause ValidationError
- Add *.pem to .gitignore
- Add services/auth/app/config.py with JWT_PRIVATE_KEY and JWT_PUBLIC_KEY
(Auth Service local config - private key never leaves this service)
- Update routes.py: sign tokens with RS256 private key
- Update deps.py + verify.py: verify tokens with RS256 public key
- Update shared/config.py: replace JWT_SECRET/JWT_ALGORITHM with
JWT_PUBLIC_KEY (for optional local verification by other services)
- Add sys.path fix in main.py for local dev without PYTHONPATH
