- add: initial database and auth services

proto/auth.proto

@@ -0,0 +1,27 @@
+syntax = "proto3";
+
+package auth;
+
+service AuthService {
+    rpc Login(LoginRequest) returns (LoginResponse);
+    rpc ValidateToken(ValidateTokenRequest) returns (ValidateTokenResponse);
+}
+
+message LoginRequest {
+    string username = 1;
+    string password = 2;
+}
+
+message LoginResponse {
+    string token = 1;
+    string user_id = 2;
+}
+
+message ValidateTokenRequest {
+    string token = 1;
+}
+
+message ValidateTokenResponse {
+    bool valid = 1;
+    string user_id = 2;
+}