Add coupon management, customer services, and update TASKS.md

Phase 5 (Admin Panel):
- Admin coupon management: full CRUD with create/edit/deactivate,
  auto-generate codes, plan restrictions multi-select, usage tracking,
  redemption history on edit page
- Add active flag migration for coupons table

Phase 4 (Customer Dashboard):
- Customer services list page with plan info and status
- Customer service detail page with network info, plan details,
  control panel links (VirtFusion/SynergyCP/Enhance), important dates
- Service status/type resolver utilities

Documentation:
- Update TASKS.md with all completed Phase 3/4/5/8 items

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

website/app/Models/Coupon.php

@@ -20,6 +20,7 @@ class Coupon extends Model
         'applies_to',
         'max_uses',
         'times_used',
+        'active',
         'expires_at',
     ];
 
@@ -30,6 +31,7 @@ class Coupon extends Model
             'applies_to' => 'array',
             'max_uses' => 'integer',
             'times_used' => 'integer',
+            'active' => 'boolean',
             'expires_at' => 'datetime',
         ];
     }
@@ -41,6 +43,10 @@ class Coupon extends Model
 
     public function isValid(): bool
     {
+        if (! $this->active) {
+            return false;
+        }
+
         if ($this->expires_at && $this->expires_at->isPast()) {
             return false;
         }