v0.2.0 - More results parsing

Added — five new Google SERP sections parsed into dedicated typed fields (ai_overview, people_also_ask, people_saying, people_also_search, related_products), plus total_results, to_json(), and to_markdown() on SearchResults.

Changed (breaking) — SearchResults.results is now organic-only. Sponsored ads, featured snippet, and all new section types live in their own named fields instead of being mixed in.

Fixed — two security hardening items (URL substring sanitization replaced with urlparse hostname allowlisting in both the detector and
DuckDuckGo parser) and least-privilege permissions: contents: read added to three CI workflows.