fix: keep search visible on narrow widths

[akira69]

Summary

Why

On the current mobile/narrow layout, the search UI disappears entirely. That makes the main browsing view much harder to use, especially once the collection grows.

The Fix

• keep the search bar visible below the md breakpoint
• keep the filters panel available on narrow widths instead of hiding the entire controls block
• treat search as a primary control so the swatch view remains usable on smaller screens

Notes

• advanced filters remain collapsible; this just keeps the primary search control available