Fix image overflow: anchor page-start tops, scale fixed-height blocks, and remove inline img baseline gap

[mettta]

• Anchor page starts to the first real child (or replaced element) for inline/contents wrappers so pageTop matches the visual top of media groups.
• When scaling fixed-height elements, wrap them to preserve layout height and prevent overflow/phantom space.
• Track/log pageTopAnchor for debugging page-start placement decisions.
• Align page-end inline images to top to eliminate the baseline gap that can trigger overflow.