Optimize backend search and evaluation pipeline

backend/services/gemini_test.go

@@ -46,3 +46,45 @@ func TestNormalizeKnownMediaPhrases(t *testing.T) {
 		t.Fatalf("expected cyberpunk city, got %q", translated)
 	}
 }
+
+func TestSelectUnevaluatedCandidatesSkipsReviewedLinks(t *testing.T) {
+	ranked := []SearchResult{
+		{Link: "https://a.example"},
+		{Link: "https://b.example"},
+		{Link: "https://c.example"},
+	}
+	reviewed := map[string]bool{
+		"https://a.example": true,
+	}
+
+	selected := SelectUnevaluatedCandidates(ranked, reviewed, 2)
+	if len(selected) != 2 {
+		t.Fatalf("expected 2 selected candidates, got %d", len(selected))
+	}
+	if selected[0].Link != "https://b.example" || selected[1].Link != "https://c.example" {
+		t.Fatalf("unexpected selection order: %#v", selected)
+	}
+}
+
+func TestRemainingGeminiCapacityShrinksWithReviewedItems(t *testing.T) {
+	reviewed := []AIRecommendation{
+		{Link: "https://a.example"},
+		{Link: "https://b.example"},
+	}
+	if got := RemainingGeminiCapacity(reviewed); got != 14 {
+		t.Fatalf("expected 14 remaining slots, got %d", got)
+	}
+}
+
+func TestGeminiVisualCacheRoundTrip(t *testing.T) {
+	service := NewGeminiService("")
+	service.setCachedVisual("image\nhttps://example.com/thumb.jpg", "abc", "image/jpeg", time.Minute)
+
+	data, mimeType, ok := service.getCachedVisual("image\nhttps://example.com/thumb.jpg")
+	if !ok {
+		t.Fatal("expected visual cache hit")
+	}
+	if data != "abc" || mimeType != "image/jpeg" {
+		t.Fatalf("unexpected cached visual data: %q %q", data, mimeType)
+	}
+}