Auto-save Collaborative Markdown Session Notes

[JoyLight00]

Background
Consultations result in checklists or resources that seekers want to retain. Losing notes due to network disconnects leads to frustration.

Goal
Implement automatic backups for the session notes text area.

Acceptance Criteria

• Store content updates to browser sessionStorage every 10 seconds.
• Restore editor state on page reload.
• Save finalized copy to server/IPFS on session completion.

Key Files
src/components/session/SessionNotes.tsx