feat: initialize backend structure with core modules and services

- Add base project structure with Cargo.toml and .env
- Implement core modules: models, services, repositories, controllers
- Set up logging, error handling, and middleware
- Configure routes and API documentation
- Add crypto and websocket functionality
- Include basic user management system

.gitignore

@@ -14,4 +14,8 @@ target/
 #  be found at https://github.com/github/gitignore/blob/main/Global/JetBrains.gitignore
 #  and can be added to the global gitignore or merged into this file.  For a more nuclear
 #  option (not recommended) you can uncomment the following to ignore the entire idea folder.
-#.idea/
+#.idea/
+
+# Added by cargo
+
+/target