fix(agent): fallback to qwen3-vl when primary returns non-json

lib/ai/smart-analyzer.ts

@@ -1353,6 +1353,22 @@ ${historyText}
 
   try {
     const { text: responseText } = await generateText(requestPayload as any);
+    const hasStructuredJson = /\{[\s\S]*\}/.test(String(responseText || ""));
+    if (hasImage && !hasStructuredJson) {
+      console.warn(
+        "[Smart Analyzer] Primary analyzer returned non-JSON for image input, fallback to hardcoded qwen3-vl",
+      );
+      const qwenFallback = await analyzeWithHardcodedQwen3VlFallback({
+        text,
+        hasImage,
+        imageUrls,
+        historyMessages,
+        context,
+        reason: "primary_non_json_response",
+      });
+      if (qwenFallback) return qwenFallback;
+    }
+
     const parsed = parseAnalysisResultFromModelText(responseText, text, hasImage);
     if (parsed) return parsed;
   } catch (error) {