[Dylan Duan (Kiddo4993)]

Resolves #3706.

Problem

If you passed a --config-file path that doesn't exist, the CLI dropped it without saying anything and carried on with defaults. A typo could therefore leave pyrit_scan or pyrit_shell pointed at an unintended server or auth mode. For example, pyrit_scan list-targets --config-file /does/not/exist.yaml ... exited 0.

Change

• pyrit/cli/_config_reader.py: added a small _resolve_config_paths helper. read_server_settings (and so read_server_url) and validate_client_config now use it instead of each building the path list themselves.
  • The auto-discovered default ~/.pyrit/.pyrit_conf is still optional.
  • An explicitly supplied config_file that doesn't exist now raises ConfigError("Config file <path> does not exist.").
• Updated the ConfigError docstring and the Raises: sections to match.

Both pyrit_scan.main and pyrit_shell.main already call validate_client_config before doing anything else, and they already catch ConfigError, print Error: ... to stderr and return 1. The new error is reported the same way as the existing malformed-config error.

Tests

• tests/unit/cli/test_config_reader.py: the two tests that asserted a missing path is silently ignored now pass config_file=None. They still check that a missing default file is fine. New tests check that a missing explicit config raises in read_server_url, read_server_settings (even when a valid default exists) and validate_client_config.
• tests/unit/cli/test_pyrit_scan.py: added test_main_missing_config_is_hard_error, modelled on the existing malformed-config test. It checks for exit code 1 and the message on stderr.
• tests/unit/cli/test_pyrit_shell.py: test_main_log_level_and_config_file passed a path that didn't exist. It now creates that file first so the test still covers what it was meant to.

I couldn't run the test suite in this environment, so these tests have not been run.

Fixes #3706

---

Happy to adjust anything or close it if it isn't a fit.