anchor_kit

Prerelease of 0.2.0 — opt in with anchor_kit: 0.2.0-dev.1. Stable users stay on 0.1.x until 0.2.0 ships.

• New middleware:
  • SizeMiddleware — reports available space on the resolved side (data['size'] = {availableWidth, availableHeight}) so a long menu can cap its height to the viewport and scroll. New "Size" example recipe.
  • AutoPlacement — picks the side with the most room (keeps the current side if it fits, else least overflow); use instead of Flip.
  • Hide — flags data['hide'] = {referenceHidden} when the anchor scrolls off-screen.
• Shift now clamps only the main axis by default (was both axes), so it no longer detaches the floating element from its anchor. Opt into crossAxis: true; rtl: true keeps the right edge for oversized elements.
• Note: SizeMiddleware collides with dart:ui's Size, hence the Middleware suffix.

• New: FloatingOverlay gains barrierDismissible + onDismiss — a transparent tap-outside-to-close barrier for dropdowns / selects / popovers.
• Example: rebuilt into a recipe gallery — placement playground, tooltip, dropdown, select (flips up), and a popover-with-arrow card. Deep-linkable via ?demo=<id> on web. Now runs on web too.
• Docs: README overhauled with screenshots, concept explanations (offset/flip/shift/arrow) and a "Known limitations" section.
• Bundles all 0.0.2 fixes below.