* fix(sessions): support stdout when output path is '-' in session export
* fix: style cleanup + extend stdout support to snapshot export
Follow-up for salvaged PR #3617:
- Fix import sys; on one line (style consistency)
- Update help text to mention - for stdout
- Apply same stdout support to hermes skills snapshot export
---------
Co-authored-by: ygd58 <buraysandro9@gmail.com>