Revert "Reduce noisy Gemini batch failure warnings"

This reverts commit 6faff4d269.

backend/services/gemini_test.go

@@ -213,18 +213,3 @@ 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)
-	}
-}