v0.28.1

Patch release for the watch UX loop.\n\n- Watch Now now runs as a flow update with stable baseline context, previous Now, current step, and current-step evidence.\n- Step boundary decisions are made by the watch flow agent instead of only raw evidence thresholds.\n- Auto Digest is now posterior: it closes the previous semantic step when the flow agent starts the next one, instead of firing from event/time cadence alone.\n- Watch monitor cards avoid empty command-completion steps and show recent evidence instead of placeholder digest text.