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

scripts/curated-snippets/libjpeg.cpp

@@ -0,0 +1,10 @@
+// libjpeg's jpeglib.h relies on stdio types being already declared.
+#include <stdio.h>
+#include <stddef.h>
+#include <jpeglib.h>
+import std;
+
+int main() {
+    std::println("libjpeg ok: lib version {}", JPEG_LIB_VERSION);
+    return 0;
+}