v1.31.8

[1.31.8] - 2026-06-29

Fixed

• Elements placed by new_section, new_row, and build_page that fill their grid cell (text, image, container, columns, repeaters) now receive constraintX: ["left","right"] (stretch) instead of ["centerLeft"] (center), so sibling elements line up edge-to-edge rather than snapping to content width and floating (the "cắn left-top / không thẳng hàng" alignment bug).
• buildElement now backfills opts.config and opts.style into runtime for factories that silently ignored them (e.g. createContainer, createMenu), fixing cases where config.isHidden was dropped and a mobile-only nav bar would remain visible on desktop.

Changed

• The button factory now defaults to content-width (widthUnit: "auto") with 28 px horizontal padding and a centred label instead of a fixed 142 px wide bar, so standalone CTAs size to their text rather than stretching edge-to-edge.
• The submit-button factory now defaults to 48 px height with 24 px horizontal padding and a centred label so form submit buttons no longer render as unstyled slivers.
• build_page, new_section, and new_row now auto-scale large fonts (fontSize ≥ 22 px, approximately 0.86× on tablet and 0.72× on mobile) and tall images (height > 320 px) on smaller breakpoints by default; an explicit responsive diff on a node still wins.
• new_element (and buildElement internally) now accepts opts.align ("left" | "center" | "right" | "fill") on any element type; "fill" sets constraintX: ["left","right"] plus widthUnit: "%" / relWidth: 100 so the element spans its column.
• get_build_guide is updated with: the grid-cell alignment rule (stretch vs. center, when each applies), button sizing and opts.align usage, auto-responsive scaling defaults, and a verified two-nav isHidden-swap pattern for building a reliable mobile menubar.