package.dds can store a version number

src/dds/package_manifest.cpp

 using namespace dds;
 
 package_manifest package_manifest::load_from_file(const fs::path& fpath) {
-    auto             kvs = lm::parse_file(fpath);
+    auto        kvs = lm::parse_file(fpath);
     package_manifest ret;
-    for (auto& pair : kvs.items()) {
-        if (pair.key() == "Name") {
-            ret.name = pair.value();
-        } else {
-            throw std::runtime_error(
-                fmt::format("Unknown key in file '{}': {}", fpath.string(), pair.key()));
-        }
-    }
+    lm::read(fmt::format("Reading package manifest '{}'", fpath.string()),
+             kvs,
+             lm::read_opt("Name", ret.name),
+             lm::read_opt("Version", ret.version),
+             lm::reject_unknown());
     return ret;
 }

src/dds/package_manifest.hpp

 
 struct package_manifest {
     std::string name;
+    std::string version = "no-version";
 
     static package_manifest load_from_file(path_ref);
 };