[Feature] : Show explicit empty and no-results states in site search #617

Reason/Context

Show explicit empty and no-results states in site search

Description

The search modal leaves its result area blank before a query and when a query has no matches, so visitors get no indication that search is ready or that there were zero results.

Steps to reproduce

1. Open the site search modal.
2. Observe the blank results area before typing.
3. Search for a string that does not occur in the site index and observe that the area remains blank.

Proposed fix

Render a short prompt before search and a clear “No results” state after an unmatched query. Include a keyboard-accessible way to clear the query and try again.