ca5c04818b
Per review: /save with no arguments prints usage (formats, filename, redact, examples) and writes nothing; the export requires an explicit format. Unknown formats print the error plus the same usage card. One shared SAVE_USAGE string in hermes_cli/session_export.py serves both the CLI and gateway handlers. args_hint updated to <json|md|html> to reflect the now-required format. Tests: bare-save and bad-format usage cases added; location tests pass an explicit format.