feat: Wikidata engine and Wikipedia knowledge infobox

- Add wikidata engine (wbsearchentities), tests, factory/planner/config
- Wikipedia REST summary: infobox from extract, thumbnail, article URL
- InfoboxView URL; render infobox list in results_inner + base styles
- Preferences Wikidata toggle; engine badge color for wikidata

Made-with: Cursor

internal/views/templates/results_inner.html

@@ -3,7 +3,26 @@
 <div id="corrections" class="correction">{{range .Corrections}}{{.}} {{end}}</div>
 {{end}}
 
-{{if or .Answers .Infoboxes}}
+{{if .Infoboxes}}
+<div class="infobox-list" role="region" aria-label="Summary">
+  {{range .Infoboxes}}
+  <aside class="infobox-card">
+    {{if .ImgSrc}}
+    <div class="infobox-image-wrap">
+      <img src="{{.ImgSrc}}" alt="" class="infobox-img" loading="lazy" width="120" height="120">
+    </div>
+    {{end}}
+    <div class="infobox-main">
+      {{if .Title}}<h2 class="infobox-title">{{.Title}}</h2>{{end}}
+      {{if .Content}}<p class="infobox-content">{{.Content}}</p>{{end}}
+      {{if .URL}}<a href="{{.URL}}" class="infobox-link" target="_blank" rel="noopener noreferrer">Read article on Wikipedia</a>{{end}}
+    </div>
+  </aside>
+  {{end}}
+</div>
+{{end}}
+
+{{if .Answers}}
 <div id="answers">
   {{range .Answers}}
   <div class="dialog-error">{{.}}</div>
@@ -38,7 +57,7 @@
   {{end}}
   {{end}}
   {{end}}
-  {{else if not .Answers}}
+  {{else if and (not .Answers) (not .Infoboxes)}}
   <div class="no-results">
     <div class="no-results-icon" aria-hidden="true">🔍</div>
     <h2>No results found</h2>