Fix: curl: (7) Failed to connect / (6) Could not resolve host / (28) Operation timed out
How to fix curl errors including 'Failed to connect to host', 'Could not resolve host', 'Operation timed out', and 'SSL certificate problem'. Covers curl exit codes 6, 7, 28, 35, 56, and 60, DNS resolution, proxy settings, timeout tuning, SSL issues, retry strategies, verbose debugging, and more.