Add pisesh — session manager TUI for the Pi coding agent

[Blue-B]

Name: pisesh
Install: npm install -g pisesh (or pi install npm:pisesh)
GitHub: https://github.com/Blue-B/pisesh

Keyboard-driven TUI to bookmark, search, rename, and resume Pi coding-agent sessions. Favorites, full-text search, custom titles, per-project view, optional AI title generation. Single-file Node script, zero runtime dependencies, MIT. The /sesh extension switches sessions in-process via ctx.switchSession().