[M5] verify-curated-db.sh + boost recipe (header-only)

scripts/curated-snippets/boost.cpp

@@ -0,0 +1,8 @@
+#include <boost/filesystem.hpp>
+import std;
+
+int main() {
+    boost::filesystem::path p{"/tmp"};
+    std::println("boost ok: {}", p.string());
+    return 0;
+}