Fix 3 schema mismatches found in full model-vs-DB audit

- Branch::users() was hasMany (users.branch_id doesn't exist), now
  belongsToMany through role_user pivot
- NotificationLog missing read_at in $fillable despite column existing
- Trainer::assignments() used wrong FK join (employee PK vs user FK),
  replaced with hasManyThrough via Employee
- POSService referenced phantom wallet.frozen_amount column
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

app/Domain/HR/Models/Trainer.php

@@ -69,10 +69,16 @@ public function availabilities(): HasMany
         return $this->hasMany(TrainerAvailability::class);
     }
 
-    public function assignments(): HasMany
+    public function assignments()
     {
-        return $this->hasMany(\App\Domain\Scheduling\Models\Assignment::class, 'user_id', 'employee_id')
-            ->whereHas('employee', fn ($q) => $q->whereColumn('employees.user_id', 'assignments.user_id'));
+        return $this->hasManyThrough(
+            \App\Domain\Scheduling\Models\Assignment::class,
+            Employee::class,
+            'id',       // employees.id
+            'user_id',  // assignments.user_id
+            'employee_id', // trainers.employee_id
+            'user_id'   // employees.user_id
+        );
     }
 
     // --- Scopes ---

app/Domain/Identity/Models/Branch.php

@@ -7,6 +7,7 @@
 use Illuminate\Database\Eloquent\Model;
 use Illuminate\Database\Eloquent\SoftDeletes;
 use Illuminate\Database\Eloquent\Relations\BelongsTo;
+use Illuminate\Database\Eloquent\Relations\BelongsToMany;
 use Illuminate\Database\Eloquent\Relations\HasMany;
 
 class Branch extends Model
@@ -33,9 +34,9 @@ public function manager(): BelongsTo
         return $this->belongsTo(\App\Models\User::class, 'manager_id');
     }
 
-    public function users(): HasMany
+    public function users(): BelongsToMany
     {
-        return $this->hasMany(\App\Models\User::class);
+        return $this->belongsToMany(\App\Models\User::class, 'role_user', 'branch_id', 'user_id');
     }
 
     public function participants(): HasMany

app/Domain/Notification/Models/NotificationLog.php

@@ -29,6 +29,7 @@ class NotificationLog extends Model
         'status',
         'error_message',
         'sent_at',
+        'read_at',
         'metadata',
     ];
 

app/Domain/POS/Services/POSService.php

@@ -87,7 +87,8 @@ public function processTransaction(
 
             // Step 5: Calculate totals
             $taxAmount = 0; // Tax configuration per academy — to be implemented
-            $serviceFeeAmount = $this->platformFeeService->calculate($subtotal);
+            $customerPays = $this->platformFeeService->customerPays();
+            $serviceFeeAmount = $customerPays ? $this->platformFeeService->calculate($subtotal) : 0;
             $totalAmount = $subtotal + $taxAmount + $serviceFeeAmount;
 
             // Step 6-7: Validate payment
@@ -214,7 +215,7 @@ private function validatePayment(POSPaymentMethod $method, int $total, ?Particip
                 throw new DomainException('الدفع بالمحفظة يتطلب تحديد المشترك');
             }
             $wallet = $this->walletService->getOrCreateWallet($participant, $participant->academy_id);
-            $availableBalance = $wallet->balance - ($wallet->frozen_amount ?? 0);
+            $availableBalance = $wallet->balance;
             if ($availableBalance < $total) {
                 throw new DomainException('رصيد المحفظة غير كافٍ');
             }