feat: 实现用户注册功能，包括数据库表结构、gRPC 服务和业务逻辑

backend/services/user-svc/proto/user.proto

@@ -0,0 +1,38 @@
+syntax = "proto3";
+
+package user;
+
+import "shared/proto/common/common.proto";
+
+// 用户服务
+service UserService {
+  // 注册用户
+  rpc Register(RegisterRequest) returns (RegisterResponse);
+  // 获取用户信息
+  rpc GetUserByAccount(GetUserByAccountRequest) returns (GetUserByAccountResponse);
+}
+
+// 注册请求
+message RegisterRequest {
+  string account = 1;
+  string password = 2;
+}
+
+// 注册响应
+message RegisterResponse {
+  string user_id = 1;
+  string account = 2;
+  common.Response response = 3;
+}
+
+// 获取用户信息请求
+message GetUserByAccountRequest {
+  string account = 1;
+}
+
+// 获取用户信息响应
+message GetUserByAccountResponse {
+  string user_id = 1;
+  string account = 2;
+  common.Response response = 3;
+}