Adds a server-side boolean setting (default: false) that controls whether
CLI sessions from state.db appear in the sidebar. Off by default so the
sidebar is clean until the user explicitly opts in.
- api/config.py: add show_cli_sessions to _SETTINGS_DEFAULTS and _SETTINGS_BOOL_KEYS
- api/routes.py: gate get_cli_sessions() call on the setting at request time
- static/index.html: checkbox in settings panel with description
- static/panels.js: load/save checkbox, refresh session list on save
- static/boot.js: load on startup alongside send_key and show_token_usage
Co-authored-by: Nathan Esquenazi <nesquena@gmail.com>