Update project structure and enhance frontend functionality

- Added a new AGENTS.md file to document the project structure and conventions.
- Updated .gitignore to include node_modules and refined cursor rules.
- Introduced new backend and frontend components for improved map interactions, including context menus and controls.
- Enhanced API composables for better admin and authentication functionalities.
- Refactored existing components for cleaner code and improved user experience.
- Updated README.md to clarify production asset serving and user setup instructions.

.gitignore

@@ -9,6 +9,7 @@ grids/
 frontend-nuxt/node_modules
 frontend-nuxt/.nuxt
 frontend-nuxt/.output
+node_modules
 
 # Old Vue 2 frontend (if present)
 frontend/node_modules
@@ -22,5 +23,6 @@ frontend/dist
 
 # OS / IDE
 .DS_Store
-.cursor/
+.cursor/*
+!.cursor/rules/
 .vscode/