feat: add object storage and points leaderboard

internal/attachments/service_test.go

@@ -0,0 +1,11 @@
+package attachments
+
+import "testing"
+
+func TestMinioPublicURL(t *testing.T) {
+	got := minioPublicURL("https://minio.example.com/", "bucket", "images/2026/10/17/a b.jpg")
+	want := "https://minio.example.com/bucket/images/2026/10/17/a%20b.jpg"
+	if got != want {
+		t.Fatalf("minioPublicURL() = %q, want %q", got, want)
+	}
+}