/explore's kind and sort segments draw §5's .bar, and no class="filters" remains in the markup #4768

/explore (src/web/studio/explore.ts:118) still draws its kind and sort segments inside <div class="filters mb">, the last class="filters" in the markup; #4688 cannot delete the .filters rules until it goes, or /explore loses its flex row.

Done:

• [ ] The /explore segment row draws §5's .bar (or .row) in place of .filters, laid out as it is now (wrapping, 8px gap, the segments scrolling on a phone).
• [ ] grep -rn "class=\"filters" src/ finds nothing; the /explore tests pass; bun scripts/design-lint.ts is clean.

Files: src/web/studio/explore.ts and its test only. The stylesheet is #4688's.