#1473 converted the title and sports-hint matches in services/search/ranking.py
to word boundaries but left two raw substring tests:
- snippet_score: 'term in snippet.lower()' — query term 'port' hits
'transport'/'support', inflating a result's relevance.
- news_quality_adjustment: 't in text or t in netloc' for the subject term —
query 'us' substring-matches 'business'/'music', so an off-topic page
wrongly escapes the off-topic penalty on a country/subject news query.
Add a _has_word helper (the same \b...\b pattern title_score already used) and
route all three word checks (title, snippet, subject) through it, so the file
stays consistent and a future partial fix can't reintroduce the same bug class.
Pure ranking refinement: scores change only for spurious substring matches; no
API or schema change.
(cherry picked from commit 22bd23f044f191bb30e43f6b68386552817f4cc3)
Co-authored-by: ghreprimand <203024559+ghreprimand@users.noreply.github.com>
