Fix ManglesUniqueOnDelete truncation for short varchar columns

The trait was appending _del_YYMMDDHHMMSS (16 chars) without respecting
column length limits, causing varchar(20) overflow on employee_number.
Now uses shorter _d{id} suffix and truncates the original value to fit
within the declared max length per field.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

app/Domain/HR/Models/Employee.php

@@ -21,6 +21,7 @@ class Employee extends Model
     use BelongsToAcademy, HasUuid, SoftDeletes, ManglesUniqueOnDelete;
 
     protected array $uniqueFieldsToMangle = ['employee_number'];
+    protected array $mangleMaxLengths = ['employee_number' => 20];
 
     protected $fillable = [
         'academy_id',

app/Domain/Shared/Traits/ManglesUniqueOnDelete.php

@@ -9,11 +9,13 @@
     public static function bootManglesUniqueOnDelete(): void
     {
         static::deleting(function ($model) {
-            $suffix = '_del_' . now()->format('ymdHis');
+            $suffix = '_d' . $model->id;
 
             foreach ($model->getUniqueFieldsToMangle() as $field) {
                 if ($model->{$field} !== null) {
-                    $model->{$field} = Str::limit($model->{$field}, 200, '') . $suffix;
+                    $maxLen = $model->getMangleMaxLength($field);
+                    $available = $maxLen - strlen($suffix);
+                    $model->{$field} = Str::limit($model->{$field}, max($available, 1), '') . $suffix;
                 }
             }
 
@@ -21,6 +23,11 @@ public static function bootManglesUniqueOnDelete(): void
         });
     }
 
+    public function getMangleMaxLength(string $field): int
+    {
+        return $this->mangleMaxLengths[$field] ?? 255;
+    }
+
     public function getUniqueFieldsToMangle(): array
     {
         return $this->uniqueFieldsToMangle ?? [];