Fix invalid translation key in AI search results

Change t('search.no_results') to t('search_page.no_results')

The key 'search.no_results' doesn't exist in translations.
The correct key is 'search_page.no_results' which contains
"Nothing was found." message.

🤖 Generated with [Claude Code](https://claude.com/claude-code

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Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>