Fix critical bugs found in pre-1.0.0 audit (#14)

* Fix critical bugs found in pre-1.0.0 audit

This commit fixes three bugs discovered during comprehensive codebase audit:

**BUG-001 (CRITICAL): Fix inverted logic in DataTransformer configuration**
- Location: FileStorageBehavior.php:404
- Problem: Custom DataTransformer from config was never used due to inverted condition
- Fix: Changed `if (!$this->getConfig('dataTransformer') instanceof ...)` to positive check
- Impact: Custom transformers can now be properly configured via behavior config

**BUG-002 (MEDIUM): Remove commented-out code**
- Location: FileStorageBehavior.php:216,220
- Problem: Two commented lines with no explanation
- Fix: Removed commented event manager toggles, added explanatory comment
- Impact: Clearer code intent, reduced maintenance confusion

**BUG-003 (MEDIUM): Fix data corruption in variant getters**
- Location: FileStorage.php:68,90
- Problem: array_shift() modified entity data as side effect in getter methods
- Fix: Use reset() instead to read first element without array modification
- Impact: Prevents progressive data corruption when getters called multiple times

All tests passing (42 tests, 146 assertions)
PHPStan Level 8 passing

See BUG_AUDIT_REPORT.md for complete audit details

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

Co-Authored-By: Claude <[email protected]>

* Delete BUG_AUDIT_REPORT.md

---------

Co-authored-by: Claude <[email protected]>

Author: dereuromark

src/Model/Behavior/FileStorageBehavior.php

@@ -213,11 +213,10 @@ public function afterSave(EventInterface $event, EntityInterface $entity, ArrayO
                 if (empty($tableConfig['className'])) {
                     $tableConfig['className'] = 'FileStorage.FileStorage';
                 }
-                //$this->getEventManager()->off('Model.afterSave');
+                // Temporarily remove behavior to prevent recursion when saving metadata
                 $this->table()->removeBehavior('FileStorage');
                 $this->table()->saveOrFail($entity, ['checkRules' => false]);
                 $this->table()->addBehavior('FileStorage', $tableConfig);
-                //$this->getEventManager()->on('Model.afterSave');
             } catch (Throwable $exception) {
                 $this->table()->delete($entity);
 
@@ -401,7 +400,9 @@ protected function getTransformer(): DataTransformerInterface
             return $this->transformer;
         }
 
-        if (!$this->getConfig('dataTransformer') instanceof DataTransformerInterface) {
+        if ($this->getConfig('dataTransformer') instanceof DataTransformerInterface) {
+            $this->transformer = $this->getConfig('dataTransformer');
+        } else {
             $this->transformer = new DataTransformer(
                 $this->table(),
             );

src/Model/Entity/FileStorage.php

@@ -61,11 +61,15 @@ public function getVariantUrl(string $variant): ?string
             return null;
         }
 
-        // Until fix is fully applied
         if (!is_string($variants[$variant]['url'])) {
             Log::write('error', 'Invalid variants url data for ' . $this->id);
 
-            return array_shift($variants[$variant]['url']);
+            // Return first element without modifying the array
+            if (is_array($variants[$variant]['url']) && count($variants[$variant]['url']) > 0) {
+                return (string)reset($variants[$variant]['url']);
+            }
+
+            return null;
         }
 
         return $variants[$variant]['url'];
@@ -83,11 +87,15 @@ public function getVariantPath(string $variant): ?string
             return null;
         }
 
-        // Until fix is fully applied
         if (!is_string($variants[$variant]['path'])) {
             Log::write('error', 'Invalid variants path data for ' . $this->id);
 
-            return array_shift($variants[$variant]['path']);
+            // Return first element without modifying the array
+            if (is_array($variants[$variant]['path']) && count($variants[$variant]['path']) > 0) {
+                return (string)reset($variants[$variant]['path']);
+            }
+
+            return null;
         }
 
         return $variants[$variant]['path'];