Add get_polymorphic_parent() helper for type_ref_columns compatibility

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

docs/CLAUDE.dist.md

@@ -828,18 +828,27 @@ Pattern recognition:
 
 ## POLYMORPHIC TYPE REFERENCES
 
-Polymorphic `*_type` columns (fileable_type, taskable_type, etc.) store BIGINT integers in the database for efficiency. The framework maps between integer IDs and class names transparently.
+Polymorphic `*_type` columns store BIGINT integers. Framework maps to class names transparently.
 
 ```php
-// Model: Declare type ref columns
 protected static $type_ref_columns = ['fileable_type'];
 
-// Usage: Code works with class name strings - conversion is automatic
-$attachment->fileable_type = 'Contact_Model';  // Stored as integer in DB
+$attachment->fileable_type = 'Contact_Model';  // Stored as integer
 echo $attachment->fileable_type;               // Reads as 'Contact_Model'
 ```
 
-**Simple Names Only**: Always use `class_basename($model)`, never `get_class($model)` (FQCNs)
+**NEVER USE morphTo()**: Laravel's `morphTo()` bypasses accessors, receives integers, crashes. Use `get_polymorphic_parent()`:
+```php
+// ❌ WRONG
+public function parent() { return $this->morphTo(...); }
+
+// ✅ CORRECT
+public function getParentAttribute() {
+    return $this->get_polymorphic_parent('parent_type', 'parent_id');
+}
+```
+
+**Simple Names Only**: Use `class_basename($model)`, never `get_class($model)`
 
 Details: `php artisan rsx:man polymorphic`