enhance embedding model support and update database schema for multi-model compatibility

src/routes/status.js

@@ -28,6 +28,13 @@ async function statusRoutes(fastify) {
       { total: 0, usable: 0 }
     );
 
+    const embeddingModelRows = db.prepare(`
+      SELECT model, COUNT(*) AS article_count
+      FROM article_embedding_store
+      GROUP BY model
+      ORDER BY article_count DESC
+    `).all();
+
     return {
       total: totals.total,
       usable: totals.usable,
@@ -35,6 +42,10 @@ async function statusRoutes(fastify) {
       bySource: Object.fromEntries(
         bySourceRows.map((row) => [row.source, { total: row.total, usable: row.usable }])
       ),
+      embeddingModels: embeddingModelRows.map((row) => ({
+        model: row.model,
+        articles: row.article_count,
+      })),
     };
   });
 }