Add contract management and invoice settings pages

- Created a new Blade view for managing brand contracts with forms for adding and editing contracts, including client and category selection.
- Implemented success message notifications for contract actions.
- Added a new Blade view for invoice settings, allowing customization of invoice number format, header branding, and default values for new invoices.
- Introduced a new PDF view for generating rate cards with customizable styles based on user profile settings.
- Developed a profile management page for rate cards, enabling users to update their identity, appearance, and visibility settings.

app/Models/Event.php

@@ -15,7 +15,7 @@ class Event extends Model
     use HasFactory, SoftDeletes;
 
     protected $fillable = [
-        'client_id', 'title', 'description', 'event_type',
+        'client_id', 'category_id', 'title', 'description', 'event_type',
         'start_time', 'end_time', 'location', 'is_priority',
         'is_all_day', 'status', 'color', 'notes',
     ];
@@ -33,6 +33,11 @@ class Event extends Model
         return $this->belongsTo(Client::class);
     }
 
+    public function category(): BelongsTo
+    {
+        return $this->belongsTo(ClientCategory::class, 'category_id');
+    }
+
     public function scopeUpcoming($query, int $hours = 24)
     {
         return $query->where('start_time', '>=', now())