feat: add ActionSheet primitive

[artiphishle]

Summary

• add ActionSheet as a generic Surface overlay primitive
• add ActionSheetItem for contextual sheet actions
• align the API with existing Surface overlay conventions: visible, onDismiss, closeOnBackdrop
• use existing Surface overlay/focus primitives: Portal, FocusScope, resolveOverlayAnimation
• export ActionSheet components and types from the Surface root barrel
• add a patch changeset

Closes #53.

Notes

This keeps ActionSheet provider-neutral and product-neutral. It does not introduce ZORA-specific semantics, platform-native action sheet bindings, complex gesture-driven bottom sheet behavior, nested menus, or command-palette behavior.

The primitive intentionally follows existing Surface conventions from Modal and Drawer rather than ZORA-style open / onOpenChange naming.

Follow-up

After this is released from Surface, ZORA can expose an app-facing ActionSheet wrapper/composition with richer item semantics as part of the Menu / ActionSheet work tracked in ankhorage/zora#205.

Verification

Not run locally in this environment because the connected GitHub API path cannot execute repo commands. Please run before merge:

bun run build
bun run lint:fix
bun run test