The setup wizard dropped non-root users at a bare shell prompt when
trying to start a system-scope gateway service. Previously
_require_root_for_system_service called sys.exit(1), which the
wizard's `except Exception` guards cannot catch (SystemExit is a
BaseException). Users with a pre-existing /etc/systemd/system unit
(e.g. from an earlier `sudo hermes setup` run) hit this whenever
they re-ran `hermes setup` as a regular user.
- Convert _require_root_for_system_service to raise a typed
SystemScopeRequiresRootError (RuntimeError subclass) instead of
sys.exit(1). The direct CLI path (`hermes gateway install|start|stop|
restart|uninstall` without sudo) still exits 1 cleanly via a new
catch at the top of gateway_command, matching the existing
UserSystemdUnavailableError pattern.
- Add _system_scope_wizard_would_need_root() pre-check and
_print_system_scope_remediation() helper. Both setup wizards
(hermes_cli/setup.py and hermes_cli/gateway.py::gateway_setup) now
detect the dead-end before prompting and print actionable guidance:
either `sudo systemctl start <service>` this time, or uninstall the
system unit and install a per-user one.
- Defense-in-depth: all 5 wizard prompt sites also catch
SystemScopeRequiresRootError and fall back to the remediation
helper if the pre-check is bypassed (race, etc.).
Tests: 12 new tests in TestSystemScopeRequiresRootError,
TestSystemScopeWizardPreCheck, TestSystemScopeRemediationOutput, and
TestGatewayCommandCatchesSystemScopeError covering the exception
contract, pre-check matrix (root vs non-root, system-only vs
user-present vs none vs explicit system=True), remediation output
for each action, and the direct-CLI exit-1 path.
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