- add: initial database and auth services

proto/database.proto

@@ -0,0 +1,34 @@
+syntax = "proto3";
+
+package database;
+
+service DatabaseService {
+    rpc GetUser(GetUserRequest) returns (GetUserResponse);
+    rpc CreateUser(CreateUserRequest) returns (CreateUserResponse);
+    rpc GetUserByUsername(GetUserByUsernameRequest) returns (GetUserResponse);
+}
+
+message GetUserRequest {
+    int32 user_id = 1;
+}
+
+message GetUserByUsernameRequest {
+    string username = 1;
+}
+
+message GetUserResponse {
+    int32 user_id = 1;
+    string username = 2;
+    string email = 3;
+    string hashed_password = 4;
+}
+
+message CreateUserRequest {
+    string username = 1;
+    string email = 2;
+    string hashed_password = 3;
+}
+
+message CreateUserResponse {
+    int32 user_id = 1;
+}