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.

AGENTS.md

@@ -0,0 +1,28 @@
+# Agent guide — hnh-map
+
+Automapper server for HnH, (mostly) compatible with [hnh-auto-mapper-server](https://github.com/APXEOLOG/hnh-auto-mapper-server). This repo is a monorepo: Go backend + Nuxt 3 frontend.
+
+## Structure
+
+| Path | Purpose |
+|------|--------|
+| `cmd/hnh-map/` | Go entry point (`main.go`) |
+| `internal/app/` | Backend logic (auth, API, map, tiles, admin, migrations) |
+| `frontend-nuxt/` | Nuxt 3 app source (pages, components, composables, layouts, `public/gfx`) |
+| `frontend/` | **Build output** — static assets served in production; generated from `frontend-nuxt/` (do not edit here) |
+| `docs/` | Architecture, API, configuration, development, deployment (part of docs is in Russian) |
+| `grids/` | Runtime data (in `.gitignore`) |
+
+## Where to look
+
+- **API:** [docs/api.md](docs/api.md) and handlers in `internal/app/` (e.g. `api.go`, `map.go`, `admin_*.go`).
+- **Configuration:** [.env.example](.env.example) and [docs/configuration.md](docs/configuration.md).
+- **Local run / build:** [docs/development.md](docs/development.md) and [CONTRIBUTING.md](CONTRIBUTING.md).
+
+## Conventions
+
+- **Backend:** Go; use `go fmt ./...`; tests with `go test ./...`.
+- **Frontend:** Nuxt 3 in `frontend-nuxt/`; public API access via composables (e.g. `useMapApi`, `useAuth`, `useAdminApi`).
+- **Ports:** Dev — frontend 3000, backend 3080 (docker-compose.dev); prod — single server 8080 serving backend + static from `frontend/`.
+
+See [.cursor/rules/](.cursor/rules/) for project-specific Cursor rules.