Rename package to shopkeeper/module-vendor-notes and fix delete button issue

- Update package name from shopkeeper/vendornotes to shopkeeper/module-vendor-notes to follow naming conventions
- Fix invalid CSS selector issue by prefixing numeric row IDs with 'row_' in getArrayRows()
- Resolves JavaScript error: "Failed to execute 'querySelectorAll' on 'Document': 'tr#0 button.action-delete' is not a valid selector"

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

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

Block/Adminhtml/Form/Field/VendorMapping.php

@@ -6,6 +6,17 @@ use Magento\Framework\DataObject;
 
 class VendorMapping extends AbstractFieldArray
 {
+    /**
+     * Initialise form fields
+     *
+     * @return void
+     */
+    protected function _construct()
+    {
+        parent::_construct();
+        $this->setTemplate('Magento_Config::system/config/form/field/array.phtml');
+    }
+
     /**
      * Prepare rendering the new field by adding all the needed columns
      */
@@ -16,17 +27,38 @@ class VendorMapping extends AbstractFieldArray
             'class' => 'required-entry',
             'style' => 'width:200px'
         ]);
-        
+
         $this->addColumn('note', [
             'label' => __('Note'),
             'class' => 'required-entry',
             'style' => 'width:400px'
         ]);
-        
+
         $this->_addAfter = false;
         $this->_addButtonLabel = __('Add Vendor Note');
     }
 
+    /**
+     * Obtain existing data from form element
+     *
+     * Each row will be instance of Varien_Object
+     *
+     * @return array
+     */
+    public function getArrayRows()
+    {
+        $result = [];
+        /** @var DataObject $row */
+        foreach (parent::getArrayRows() as $key => $row) {
+            // Ensure row IDs are prefixed with a non-numeric character
+            if (is_numeric($key)) {
+                $key = 'row_' . $key;
+            }
+            $result[$key] = $row;
+        }
+        return $result;
+    }
+
     /**
      * Prepare existing row data object
      *