feat: basic music backend

proto/settings.proto

@@ -0,0 +1,43 @@
+syntax = "proto3";
+
+import 'google/protobuf/empty.proto';
+
+package settings;
+
+service Settings {
+	rpc ListPaths(google.protobuf.Empty) returns (SettingsData);
+	rpc AddPath(AddPathRequest) returns (AddPathResponse);
+	rpc DeletePath(DeletePathRequest) returns (DeletePathResponse);
+	rpc RefreshPath(RefreshPathRequest) returns (RefreshPathResponse);
+}
+
+message SettingsData {
+	repeated LibraryPath library_paths = 1;
+}
+
+message LibraryPath {
+	uint64 id = 1;
+	string path = 2;
+}
+
+message AddPathRequest {
+	string path = 1;
+}
+
+message AddPathResponse {
+	uint64 id = 1;
+}
+
+message DeletePathRequest {
+	uint64 id = 1;
+}
+
+message DeletePathResponse {
+}
+
+message RefreshPathRequest {
+	uint64 id = 1;
+}
+
+message RefreshPathResponse {
+}