OpenSSL 3.x ignores intermediate CA certs in -CAfile (verify code 20)
but correctly builds chains with -CApath (verify code 0).
All three clients now use capath:
- service.py: ssl.create_default_context(capath=...)
- _llm_http.py: verify='/etc/ssl/certs/'
- preview_llm_client.py: verify='/etc/ssl/certs/'
check_llm_certs.py rewritten for clarity.