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/base.html

@@ -528,6 +528,7 @@
     .result[data-engine="braveapi"], .engine-badge[data-engine="braveapi"] { --engine-accent: #ff6600; }
     .result[data-engine="qwant"], .engine-badge[data-engine="qwant"] { --engine-accent: #5c97ff; }
     .result[data-engine="wikipedia"], .engine-badge[data-engine="wikipedia"] { --engine-accent: #a3a3a3; }
+    .result[data-engine="wikidata"], .engine-badge[data-engine="wikidata"] { --engine-accent: #339966; }
     .result[data-engine="github"], .engine-badge[data-engine="github"] { --engine-accent: #8b5cf6; }
     .result[data-engine="reddit"], .engine-badge[data-engine="reddit"] { --engine-accent: #ff4500; }
     .result[data-engine="youtube"], .engine-badge[data-engine="youtube"] { --engine-accent: #ff0000; }
@@ -538,6 +539,73 @@
     .result[data-engine="ddg_images"], .engine-badge[data-engine="ddg_images"] { --engine-accent: #de5833; }
     .result[data-engine="qwant_images"], .engine-badge[data-engine="qwant_images"] { --engine-accent: #5c97ff; }
 
+    /* Wikipedia / knowledge infobox */
+    .infobox-list {
+      margin-bottom: 1.25rem;
+    }
+
+    .infobox-card {
+      display: flex;
+      flex-direction: row;
+      flex-wrap: wrap;
+      gap: 1rem;
+      align-items: flex-start;
+      padding: 1rem 1.15rem;
+      background: var(--bg-secondary);
+      border: 1px solid var(--border);
+      border-radius: var(--radius-md);
+      box-shadow: var(--shadow-sm);
+    }
+
+    .infobox-image-wrap {
+      flex-shrink: 0;
+      width: 120px;
+      height: 120px;
+      border-radius: var(--radius-sm);
+      overflow: hidden;
+      background: var(--bg-tertiary);
+      border: 1px solid var(--border);
+    }
+
+    .infobox-img {
+      width: 100%;
+      height: 100%;
+      object-fit: cover;
+      display: block;
+    }
+
+    .infobox-main {
+      flex: 1;
+      min-width: min(100%, 220px);
+    }
+
+    .infobox-title {
+      font-size: 1.15rem;
+      font-weight: 600;
+      color: var(--text-primary);
+      margin-bottom: 0.5rem;
+      line-height: 1.3;
+    }
+
+    .infobox-content {
+      font-size: 0.9rem;
+      color: var(--desc-color);
+      line-height: 1.55;
+      margin-bottom: 0.65rem;
+    }
+
+    .infobox-link {
+      display: inline-block;
+      font-size: 0.875rem;
+      font-weight: 500;
+      color: var(--title-link);
+      text-decoration: none;
+    }
+
+    .infobox-link:hover {
+      text-decoration: underline;
+    }
+
     .dialog-error {
       padding: 0.65rem 0.85rem;
       margin-bottom: 0.75rem;

internal/views/templates/preferences.html

@@ -40,6 +40,10 @@
           <input type="checkbox" name="engine" value="wikipedia" checked>
           <span>Wikipedia</span>
         </label>
+        <label class="engine-toggle">
+          <input type="checkbox" name="engine" value="wikidata" checked>
+          <span>Wikidata</span>
+        </label>
         <label class="engine-toggle">
           <input type="checkbox" name="engine" value="github">
           <span>GitHub</span>

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>