Add article.listSearchIndex for client-side search preload

Returns all company articles with id, sku, name, and eans as a flat
array. Walks the category tree to find reachable articles. Single
query using recursive CTE + FOR JSON for eans.

src/sql/article.js

@@ -160,6 +160,46 @@ FROM brand
 WHERE id = @brandId AND company_id = @companyId
 `;
 
+/**
+ * Company-wide article search index.
+ * Returns one row per article with id, sku, name, and all eans as a JSON array.
+ * Used by the client for local search / autocomplete.
+ */
+export const SEARCH_ARTICLES = `
+;WITH category_tree AS (
+    SELECT id
+    FROM category
+    WHERE id = @rootCategoryId
+
+    UNION ALL
+
+    SELECT c.id
+    FROM category c
+    INNER JOIN category_tree ct ON c.parent_id = ct.id
+)
+SELECT
+    a.id,
+    a.sku,
+    at.name,
+    (
+        SELECT ae.ean
+        FROM articleean ae
+        WHERE ae.article_id = a.id
+        ORDER BY ae.ean
+        FOR JSON PATH
+    ) AS eansJson
+FROM article a
+LEFT JOIN articletext at
+    ON at.article_id = a.id AND at.language_id = @languageId
+WHERE EXISTS (
+    SELECT 1
+    FROM categoryarticle ca
+    INNER JOIN category_tree ct ON ct.id = ca.category_id
+    WHERE ca.article_id = a.id
+)
+ORDER BY a.id
+`;
+
 /**
  * Single-query replacement for resolveArticleBySku + queryBySku.
  * Resolves SKU → article + company + auth, then loads full article detail