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.
Rework of salvaged PR #6372 (@ag9920) onto current main:
- /save promoted from CLI-only JSON snapshot to a cross-platform session
export: `/save [json|md|html] [filename] [redact]` on CLI and every
gateway platform (sent as a document via adapter.send_document).
- Rendering routes through the existing shared renderers
(hermes_cli/session_export.py + session_export_html.py) instead of the
PR's new hermes_state formatter — new helpers normalize_save_format /
render_session_for_save / default_save_filename are shared by both
surfaces.
- `redact` arg runs the export through the force-mode secret redaction
pass (session_export_md.redact_session_data) before writing.
- Gateway handler awaits AsyncSessionDB correctly, sanitizes user-supplied
filenames with basename, and lands in gateway/slash_commands.py (the
handlers moved out of gateway/run.py since the PR was authored).
- /export stays profile export (name collision resolved: session export
lives on /save).
- Slack 50-slash cap curation: /platform moves to the /hermes-only set to
free a native slot for /save (parity test updated rationale comment).
- Folds in PR #62268 (@briandevans): None title/model coalescing in the
single-session HTML export.
Closes#4249. Closes#51200.
