trackForward read geometry.coordinates, a key the backend never emits, and
had no bbox branch - the action silently no-op'd for every shape (flagged
dead in docs/audit-2026-08-07.md:103).
- bbox points used as-is, polygon reduced to its bounding box
- guards speak instead of returning silently
- a frame SAM3 refuses no longer aborts the remaining frames
- a press during an in-flight run is ignored (would double-write)
- REQ-189 added; non-goal requirements.md:22 amended to keep exemplar
propagation out while admitting this one-shot hand-off
asus
b71f1d4bf2
