Uses the Stack Exchange API v3 (/search/advanced) to find questions
sorted by relevance. No API key required (300 req/day); optionally
configure via STACKOVERFLOW_KEY env var or [engines.stackoverflow].
Results include score, answer count, view count, and tags in the
snippet. Assigned to the 'it' category, triggered by the IT category
tab or explicit engine selection.
6 tests covering parsing, edge cases, and helpers.
