done restructure calculation retribution

app/Models/CalculableRetribution.php

@@ -0,0 +1,64 @@
+<?php
+
+namespace App\Models;
+
+use Illuminate\Database\Eloquent\Model;
+use Illuminate\Database\Eloquent\Relations\BelongsTo;
+use Illuminate\Database\Eloquent\Relations\MorphTo;
+
+class CalculableRetribution extends Model
+{
+    protected $fillable = [
+        'retribution_calculation_id',
+        'calculable_id',
+        'calculable_type',
+        'is_active',
+        'assigned_at',
+        'notes',
+    ];
+
+    protected $casts = [
+        'is_active' => 'boolean',
+        'assigned_at' => 'timestamp',
+    ];
+
+    /**
+     * Get the owning calculable model (polymorphic)
+     */
+    public function calculable(): MorphTo
+    {
+        return $this->morphTo();
+    }
+
+    /**
+     * Get the retribution calculation
+     */
+    public function retributionCalculation(): BelongsTo
+    {
+        return $this->belongsTo(RetributionCalculation::class);
+    }
+
+    /**
+     * Scope: Only active assignments
+     */
+    public function scopeActive($query)
+    {
+        return $query->where('is_active', true);
+    }
+
+    /**
+     * Scope: Only inactive assignments
+     */
+    public function scopeInactive($query)
+    {
+        return $query->where('is_active', false);
+    }
+
+    /**
+     * Scope: For specific calculable type
+     */
+    public function scopeForType($query, string $type)
+    {
+        return $query->where('calculable_type', $type);
+    }
+}