fix(wiki): detect wiki sources by config.kind, not type

A converted source keeps its origin type (e.g. crawler) with the wiki-ness in config.kind=wiki (D5/D20), so the UI's type==='wiki' checks treated converted sources as normal (wrong view, convert action still offered). Sources.tsx now keys isWiki + the view branch on config.kind==='wiki' (with a type fallback for blank-created wikis). The paginated endpoint already returns config.

frontend/src/settings/Sources.tsx

@@ -337,7 +337,7 @@ export default function Sources({
     index: number,
     document: Doc,
   ): SourceMenuOption[] => {
-    const isWiki = document.type === 'wiki';
+    const isWiki = document.config?.kind === 'wiki' || document.type === 'wiki';
     // 'team' viewers cannot write; convert is owner/editor only.
     const canEdit =
       document.ownership !== 'team' || document.team_access === 'editor';
@@ -464,7 +464,8 @@ export default function Sources({
 
   return documentToView ? (
     <div className="mt-8 flex flex-col">
-      {documentToView.type === 'wiki' ? (
+      {documentToView.config?.kind === 'wiki' ||
+      documentToView.type === 'wiki' ? (
         <WikiViewer
           docId={documentToView.id || ''}
           sourceName={documentToView.name}