fix: top bar search resets state instead of refining

[saivats]

What

• Fixes Search in top bar should start a new search #306 — searching from the top bar now always starts a fresh
  search instead of combining with the previous search state.

Root cause

In submitSuggestion() in search-bar.ts, the non-suggestion path
(plain text + Enter) only set this.query and called this.search().
But buildParams() was still including old facet filters via
_facetsFilters(), appending them to the new query and causing the
combined search and backend 500 error.

Fix

Added this.resetFacets(false) before setting the new query in the
else branch of submitSuggestion(). This reuses the existing
resetFacets() method already used by the Reset button.

Testing

• Added a test in search-bar_test.ts verifying resetFacets is
  called when user submits plain text search
• Manually verified: searching "categories:teas" then "categories:pastas"
  now returns only pasta results

[saivats]

@alexgarel @teolemon — fix for #306 is ready for review.
1 line change in submitSuggestion() + a test. All 24 tests pass.

[alexgarel]

@saivats great, I'll validate my suggestion, it's better to have more comments! But I will then validate
Thank you for this valuable contribution