The sigma-clip pass recomputed the stencil distances over the whole box to find the same background
ring pixels pass A had just summed. Pass A now keeps their values and radial offsets in its own
order, and the clip runs over them - the same pixels, the same sums.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01D1G8gJVAy6gp1K5Dz3NE5C