[M5+] add resolver::devbox_resolve (search.devbox.sh)

src/resolver/resolver.cppm

@@ -136,4 +136,26 @@ auto discover(const std::string& name, const std::string& version_spec,
               const std::filesystem::path& scratch_root, const BuildFn& build_fn)
     -> util::Result<Discovered>;
 
+// Output of devbox's /v1/resolve API. We capture only the fields cargoxx
+// uses; the response carries far more metadata (license, summary, per-
+// system store hashes) that we deliberately ignore.
+struct DevboxResolution {
+    std::string name;
+    std::string version;
+    std::string commit_hash;
+    std::vector<std::string> attr_paths;
+};
+
+// Pure: parse the JSON body of GET https://search.devbox.sh/v1/resolve.
+// `commit_hash` must be present and non-empty; other fields tolerate
+// absence by leaving themselves blank.
+auto parse_devbox_resolve(std::string_view json)
+    -> util::Result<DevboxResolution>;
+
+// Calls GET https://search.devbox.sh/v1/resolve?name=<n>&version=<v>
+// via curl. 404 → ResolutionUnknownPackage; transport / parse errors →
+// ResolutionNetworkError.
+auto devbox_resolve(const std::string& name, const std::string& version)
+    -> util::Result<DevboxResolution>;
+
 } // namespace cargoxx::resolver