使用了AI重构项目，并完善了一部分后台问题

internal/api/validation_test.go

@@ -0,0 +1,42 @@
+package api
+
+import "testing"
+
+func TestURLValidation(t *testing.T) {
+	for _, value := range []string{"https://example.com", "http://localhost:8080"} {
+		if !validHTTPURL(value) {
+			t.Errorf("expected valid site URL: %s", value)
+		}
+	}
+	for _, value := range []string{"javascript:alert(1)", "//example.com", "example.com"} {
+		if validHTTPURL(value) {
+			t.Errorf("expected invalid site URL: %s", value)
+		}
+	}
+	for _, value := range []string{"mailto:a@example.com", "tel:+8613800000000", "https://example.com"} {
+		if !validContactURL(value) {
+			t.Errorf("expected valid contact URL: %s", value)
+		}
+	}
+	for _, value := range []string{"/uploads/qr.png", "https://example.com/qr.png"} {
+		if !validQRCode(value) {
+			t.Errorf("expected valid QR path: %s", value)
+		}
+	}
+	for _, value := range []string{"/uploads/../secret.png", "data:image/png;base64,abc"} {
+		if validQRCode(value) {
+			t.Errorf("expected invalid QR path: %s", value)
+		}
+	}
+}
+
+func TestPercentageCountsSumsToOneHundred(t *testing.T) {
+	values := percentageCounts(map[string]int{"direct": 1, "search": 1, "other": 1}, 3)
+	total := 0
+	for _, value := range values {
+		total += value["value"].(int)
+	}
+	if total != 100 {
+		t.Fatalf("percentage total = %d, want 100", total)
+	}
+}