Fix docs command spacing

[trsoliu]

Summary

• restore clear visual spacing between syntax-highlighted command tokens
• widen quality-gate command layout from squeezed three columns to breathable two columns
• keep hero proof metrics away from divider lines and prevent desktop stat wrapping
• extend docs code block checks to guard command spacing and gate layout

Verification

• Playwright desktop/mobile spacing audit on docs homepage
• pnpm typecheck
• pnpm test
• pnpm check:ui
• pnpm registry:build
• pnpm build:miniprogram
• pnpm build:docs
• pnpm --filter vekui test