feat: add web search block functionality and integrate with existing plugins

- Introduced a new web search block plugin to handle web search queries and results.
- Updated copilot, doc block, and pro block plugins to include web search context in AI completions.
- Implemented utility functions for parsing and building web search markdown.
- Enhanced API to support web search requests and responses.
- Added configuration for web search URL and timeout settings.
- Updated size limit checks to account for web search content.

reports/searxng/searxng-expanded-final-engines-20260609-133910.csv

@@ -0,0 +1,27 @@
+engine,elapsed_ms,result_count,result_engines,unresponsive,quality_score
+bing,165.2,9,"[""bing""]",[],65.0
+searchmysite,298.6,10,"[""searchmysite""]",[],70.0
+duckduckgo news,379.5,30,"[""duckduckgo news""]",[],90.0
+360search,406.8,5,"[""360search""]",[],45.0
+reuters,472.4,20,"[""reuters""]",[],63.0
+github,544.7,30,"[""github""]",[],63.0
+startpage,1045.3,10,"[""startpage""]",[],61.0
+superuser,1057.6,8,"[""superuser""]",[],39.0
+mwmbl,1382.2,34,"[""mwmbl""]",[],82.0
+gitlab,1461.2,20,"[""gitlab""]",[],61.0
+yep,1492.8,20,"[""yep""]",[],90.0
+mdn,1585.1,10,"[""mdn""]",[],43.0
+stackoverflow,1598.3,10,"[""stackoverflow""]",[],43.0
+microsoft learn,1620.8,10,"[""microsoft learn""]",[],43.0
+askubuntu,1685.8,10,"[""askubuntu""]",[],43.0
+naver news,1694.3,10,"[""naver news""]",[],61.0
+docker hub,1762.3,10,"[""docker hub""]",[],33.0
+arxiv,1905.2,10,"[""arxiv""]",[],43.0
+npm,2053.9,25,"[""npm""]",[],63.0
+pkg.go.dev,2071.5,50,"[""pkg.go.dev""]",[],47.0
+sourcehut,2286.6,2,"[""sourcehut""]",[],27.0
+openalex,3019.1,10,"[""openalex""]",[],42.0
+crowdview,3596.9,40,"[""crowdview""]",[],84.0
+hackernews,3723.3,30,"[""hackernews""]",[],63.0
+pubmed,4589.8,20,"[""pubmed""]",[],62.0
+crossref,4708.4,18,"[""crossref""]",[],53.22