Module commands 

The :pi ex-command — launch the pi agent’s native TUI in a terminal buffer with pi-mode activated on it.

Per feedback_mode_owns_its_surface, both the binding (the command name) and the body live here; the host action (spawning the terminal + activating the minor) is requested through the [Effect] vocabulary — the host boundary — not a bespoke channel, exactly like :opencode.

Functions

register_pi_ex_commands

Register :pi against registry. Called from super::install.