Master dimensions move from a 2048 long-edge rule to a total-pixel
budget (normalizedImageMaxPixels, default 2048x2048) with an 8192
long-edge cap, so extreme aspect ratios keep short-edge resolution.
The shared quality ladder and lazy execution move to encoding.ts,
review-round doc fixes land across attachment and llm packages, and
the superseded facts in the unified-image-pipeline note now describe
the shipped routing.
creatixchu