feat: Add Lawn Care Tips section and improve Dashboard layout

Models/LawnCareTip.cs

@@ -0,0 +1,30 @@
+using System.ComponentModel.DataAnnotations;
+
+namespace turf_tasker.Models;
+
+public enum TipCategory
+{
+    Mowing,
+    Watering,
+    Fertilizing,
+    [Display(Name = "Weed Control")]
+    WeedControl,
+    Aeration,
+    General
+}
+
+public class LawnCareTip
+{
+    public int Id { get; set; }
+    
+    [Required]
+    [StringLength(100)]
+    public string Title { get; set; } = string.Empty;
+    
+    [Required]
+    public TipCategory Category { get; set; }
+    
+    [Required]
+    [DataType(DataType.MultilineText)]
+    public string Content { get; set; } = string.Empty;
+}