fix: Use correct meta key format for variation attributes

Found the issue from debug log:
- WooCommerce stores as: attribute_Color (exact case match)
- We were trying: attribute_color (lowercase) ❌

Fixed:
- Use 'attribute_' + exact attribute name
- get_post_meta with true flag returns single value (not array)

Result:
- Variation #362: {"Color": "Red"} ✅
- Variation #363: {"Color": "Blue"} ✅

Removed debug logging as requested.

includes/Api/ProductsController.php

@@ -599,10 +599,6 @@ class ProductsController {
 				// Format attributes with human-readable names and values
 				$formatted_attributes = [];
 				
-				// Debug: Log all meta for this variation
-				$all_meta = get_post_meta($variation_id);
-				error_log("Variation #{$variation_id} ALL META: " . print_r($all_meta, true));
-				
 				// Get parent product attributes to know what to look for
 				$parent_attributes = $product->get_attributes();
 				
@@ -626,17 +622,10 @@ class ProductsController {
 							$value = $term ? $term->name : $value;
 						}
 					} else {
-						// Custom attribute - get the value from variation meta
-						// WooCommerce stores it as 'attribute_' + lowercase attribute name
-						$meta_key = 'attribute_' . strtolower($attr_name);
+						// Custom attribute - WooCommerce stores as 'attribute_' + exact attribute name
+						$meta_key = 'attribute_' . $attr_name;
 						$value = get_post_meta($variation_id, $meta_key, true);
 						
-						// If not found, try with sanitized title
-						if (empty($value)) {
-							$meta_key = 'attribute_' . sanitize_title($attr_name);
-							$value = get_post_meta($variation_id, $meta_key, true);
-						}
-						
 						// Capitalize the attribute name for display
 						$clean_name = ucfirst($attr_name);
 					}