feat: Implement a customizable dashboard with user preferences and a dynamic widget system.

src/backend/Zentral.API/Controllers/DashboardController.cs

@@ -0,0 +1,77 @@
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.EntityFrameworkCore;
+using Zentral.Domain.Entities;
+using Zentral.Infrastructure.Data;
+
+namespace Zentral.API.Controllers;
+
+[ApiController]
+[Route("api/[controller]")]
+public class DashboardController : ControllerBase
+{
+    private readonly ZentralDbContext _context;
+
+    public DashboardController(ZentralDbContext context)
+    {
+        _context = context;
+    }
+
+    [HttpGet("preference")]
+    public async Task<ActionResult<DashboardPreferenceDto>> GetPreference()
+    {
+        // TODO: Implement proper user identification
+        // For now, we'll use the first active user or a specific test user
+        var user = await _context.Utenti.FirstOrDefaultAsync(u => u.Attivo);
+        if (user == null)
+        {
+            return NotFound("No active user found");
+        }
+
+        var preference = await _context.UserDashboardPreferences
+            .FirstOrDefaultAsync(p => p.UtenteId == user.Id);
+
+        if (preference == null)
+        {
+            return Ok(new DashboardPreferenceDto { LayoutJson = "[]" });
+        }
+
+        return Ok(new DashboardPreferenceDto { LayoutJson = preference.LayoutJson });
+    }
+
+    [HttpPost("preference")]
+    public async Task<ActionResult> SavePreference([FromBody] DashboardPreferenceDto dto)
+    {
+        // TODO: Implement proper user identification
+        var user = await _context.Utenti.FirstOrDefaultAsync(u => u.Attivo);
+        if (user == null)
+        {
+            return NotFound("No active user found");
+        }
+
+        var preference = await _context.UserDashboardPreferences
+            .FirstOrDefaultAsync(p => p.UtenteId == user.Id);
+
+        if (preference == null)
+        {
+            preference = new UserDashboardPreference
+            {
+                UtenteId = user.Id,
+                LayoutJson = dto.LayoutJson
+            };
+            _context.UserDashboardPreferences.Add(preference);
+        }
+        else
+        {
+            preference.LayoutJson = dto.LayoutJson;
+            preference.UpdatedAt = DateTime.UtcNow;
+        }
+
+        await _context.SaveChangesAsync();
+        return Ok();
+    }
+}
+
+public class DashboardPreferenceDto
+{
+    public string LayoutJson { get; set; } = "[]";
+}