Adds figma.exposeInstanceSwap(slots, candidates, propertyName), which
exposes one or more nested instances as an instance-swap slot — the
enclosing component (or component set, walking up past intermediate
variant members) gets an INSTANCE_SWAP property offering the given
candidates, and each slot instance is tagged to respond to it. Mirrors
Figma's "Create component property > Instance swap", letting a designer
pick which component fills a slot (e.g. an icon on a button) instead of
the slot being baked-in static content.
Exposed as the expose_instance_swap MCP/CLI/chat tool.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>