SearchPopup changelog

• 2026-10-07: Search panel composition is now provided as a Composite Block. The earlier SearchPopup floating container remains removed; the new block does not restore that implementation.

The built-in search icon reuses ComponentIcon search with a 24px canvas. Its source is resource-base/raw-assets/icons/snowui/Search.svg with viewBox 0 0 32 32; paths, whitespace, and proportions are unchanged. IconProvider can replace it globally.