Symptom

The KRILL_DEMO_CONTROL file-channel hook (added in #580) understands select / view / center / fit / reset — all canvas operations. There was no way to ask the app to change screen. Reaching the Swarm Work screen from an automation pipeline required clicking the 🧠 rail toggle at a calibrated pixel position derived from layout constants, which breaks silently (wrong click target, no error) the moment the rail toggles are added to, reordered, or resized.

Root cause

Not a bug — a missing capability. ScreenCore only exposed toggleSwarmScreen(), a flip, so even a code-level fix couldn’t drive the Swarm Work view to a known state — two toggles from an unknown starting state can land on either side.

Fix

Prevention

When a ScreenCore flag is meant to be driven from outside the UI (a demo hook, a test, a future scripting surface), expose an idempotent setter next to any toggle from the start — a toggle-only API silently assumes the only caller is a button that already knows the current state.