Reduce noisy Gemini batch failure warnings

backend/services/gemini_test.go

@@ -213,3 +213,18 @@ func TestMergeRecommendationsExcludesIrrelevantAndPendingFiller(t *testing.T) {
 		t.Fatalf("unexpected merged result: %#v", merged)
 	}
 }
+
+func TestFilterHardGeminiErrorsIgnoresLowValueVisualFailures(t *testing.T) {
+	errs := []string{
+		"candidate thumbnail is low value",
+		"no candidate thumbnails or preview frames could be fetched for gemini vision",
+		"gemini vision JSON extraction failed: no complete JSON object found",
+	}
+	filtered := filterHardGeminiErrors(errs)
+	if len(filtered) != 1 {
+		t.Fatalf("expected only hard errors to remain, got %#v", filtered)
+	}
+	if !strings.Contains(filtered[0], "JSON extraction failed") {
+		t.Fatalf("unexpected filtered errors: %#v", filtered)
+	}
+}