Specification: Bundled screen rules for Pi, OpenCode and Cursor

Created: 2026-10-09. Status: clarified.

Spec 027 added [[screen]] rules but shipped none, so out of the box a pane running Pi (which has no hooks) still never shows working, blocked or done. This spec ships herdr's screen rules for the agents whose rules fit the engine with two small additions, following docs/14 directive 3.

Acceptance

1. A [[screen]] rule may add all (every regex must match) and not (no regex may match) to regex (any regex matches). It needs regex or all; an invalid regex in any list rejects the manifest.
2. signaltty ships rules for pi, opencode and cursor, ported from herdr (Apache-2.0, attributed in each file), each ending with a lowest-priority idle rule: like herdr, a known agent that shows no working or blocked sign is idle, so a finished turn becomes done + unread.
3. If any user manifest of a kind declares [[screen]] rules, those replace the bundled rules of that kind; otherwise the bundled rules apply. Hook gating and transitions are unchanged from spec 027.
4. Fixture tests drive each bundled rule set through a representative working, blocked (OpenCode, Cursor) and idle screen, plus near-miss screens. A real-PTY test shows a pi pane going working → done with no manifests.

Scope and clarification

Claude and Codex rules need herdr's prompt-aware regions (prompt_box_body, after_last_prompt_marker, …) and are deferred; those agents usually report through hooks anyway. Fixtures are written from the rules' text, not captured from the real CLIs, so they prove the port, not the CLIs' current output. agent.explain stays deferred. No unresolved requirements remain.