lutece-patterns

# Lutece 8 — Architecture Patterns

Reference patterns extracted from `~/.lutece-references/lutece-core/`. Use these as the canonical way to write Lutece 8 code.

## Layered Architecture

Every Lutece feature follows 5 layers, top to bottom. Never skip a layer.

```
JspBean / XPage          ← web layer (request handling, validation, templates)
    ↓
Service                  ← business logic, cross-cutting concerns
    ↓
Home                     ← static facade (CDI lookup of DAO, cache coordination)
    ↓
DAO                      ← data access (DAOUtil, SQL, try-with-resources)
    ↓
Entity                   ← POJO (fields, getters/setters, interfaces)
```

## 1. Entity

```java
public class Task implements Serializable {
    private static final long serialVersionUID = 1L;

    private int _nIdTask;
    private String _strTitle;
    private boolean _bCompleted;
    private Timestamp _dateCreation;

    // Getters/setters only. No logic. No annotations except validation.
}
```

**Field prefixes**: `_str` (String), `_n` (int), `_b` (boolean), `_date` (Timestamp), `_list` (Collection).

**Interfaces to implement when needed**:
- `RBACResource` → RBAC permissions (`getResourceTypeCode()`, `getResourceId()`)
- `AdminWorkgroupResource` → workgroup filtering
- `IExtendableResource` → resource extension system

## 2. DAO

```java
@ApplicationScoped
public final class TaskDAO implements ITaskDAO {
    private static final String SQL_QUERY_SELECTALL = "SELECT id_task, title, completed FROM myplugin_task";
    private static final String SQL_QUERY_SELECT     = SQL_QUERY_SELECTALL + " WHERE id_task = ?";
    private static final String SQL_QUERY_INSERT     = "INSERT INTO myplugin_task ( title, completed ) VALUES ( ?, ? )";
    private static final String SQL_QUERY_UPDATE     = "UPDATE myplugin_task SET title = ?, completed = ? WHERE id_task = ?";
    private static final String SQL_QUERY_DELETE     = "DELETE FROM myplugin_task WHERE id_task = ?";

    @Override
    public void