Herdr workflow extension

This repo-local extension is enabled when Pi is running in a Herdr-managed pane. It adds /workflow agent actions for opening a live session or a completed agent session in a Herdr pane.

Set fully inspectable mode in the global workflow settings file (~/.pi/agent/pi-extensible-workflows/settings.json):

{ "extensions": { "herdr": { "enableFullyInspectableMode": true } } }

Fully inspectable mode launches each workflow agent in a dedicated labeled Herdr workspace and hides the manual live-session action while the agent is active.

Live handoff pauses the local SDK at a turn boundary. The originating Pi TUI shows the handed-off agent's working state and idle or completed state before handback while the Herdr pane owns the task. Pane exit, /quit, or a pane that returns idle after Herdr has observed it working returns ownership to the local SDK. Completed agent sessions can be opened in a separate Herdr pane from the navigator without taking ownership. The monitor relies on Herdr's built-in Pi screen detection and therefore cannot distinguish an aborted turn from a completed one. In Pi's default keybindings, interrupt is Escape; use double-Escape to abort a turn. A single Ctrl-C clears the editor and double-Ctrl-C exits Pi, so Ctrl-C is not a handback signal. Lifecycle reports from this extension are advisory when Herdr's built-in Pi integration has authority. Inline extension factories are materialized as temporary explicit extensions in the Herdr pane.