Tune default web control density and typography

New web projects currently render with touch-first sizing at every breakpoint: every grid row and control is 44px tall, vertical gutters are 16px, text defaults to 13px, and a freshly dropped Button is a single grid column wide, so even a short caption like "Push Me" truncates to "Push…". On desktop-width pages this reads as chunky, oversized, and low-density compared with mainstream web applications.

This change rebalances the default web appearance to the density mainstream web UIs use, while staying well above accessibility minimums:

• Grid rows and controls shrink from 44px to 38px, and vertical gutters from 16px to 12px (horizontal gutters stay 16px).
• Default control text grows from 13px to 14px, so controls look proportionally tighter rather than simply smaller.
• Button and input padding is reduced (buttons from 10px 16px to 8px 12px; inputs from 10px 12px to 8px 12px), and checkbox rows and select/colour-picker controls use the same 38px height.
• A new Button now defaults to a two-column placement, so typical captions fit without ellipsis.

Existing projects keep working unchanged: layouts store grid placements as row/column counts, so saved pages render at the new metrics without migration, and there is no format or protocol change.

Accessibility context: 44px was the WCAG 2.5.5 (Level AAA) and Apple HIG touch target. The new 38px default remains well above the WCAG 2.2 Level AA minimum target size of 24px, matching the default density of the most widely used web frameworks.