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/ContentBrief.php

@@ -15,7 +15,7 @@ class ContentBrief extends Model
     use HasFactory, SoftDeletes;
 
     protected $fillable = [
-        'client_id', 'title', 'platform', 'content_type', 'status',
+        'client_id', 'category_id', 'title', 'platform', 'content_type', 'status',
         'hook', 'body', 'cta', 'script', 'caption', 'hashtags',
         'target_date', 'posted_date', 'posted_url', 'sort_order', 'notes',
     ];
@@ -31,6 +31,11 @@ class ContentBrief extends Model
         return $this->belongsTo(Client::class);
     }
 
+    public function category(): BelongsTo
+    {
+        return $this->belongsTo(ClientCategory::class, 'category_id');
+    }
+
     public function getPlatformIconAttribute(): string
     {
         return match($this->platform) {