Release version 1.2.7 - Fix v1.2.6 regressions (both issues still not working)

Fixed both critical issues that were not resolved in v1.2.6:

1. Variable Product Forms Still Not Showing (Critical)
   - v1.2.6 used wrong hook (woocommerce_product_options_pricing)
   - That hook only fires for simple products, not variable products
   - Changed to woocommerce_product_options_general_product_data
   - This hook fires for all product types after general tab
   - Forms now appear correctly for variable product parents

2. Table Headers Still Visible When Empty (Critical)
   - CSS :has() pseudo-class wasn't working reliably
   - Implemented JavaScript + CSS class approach instead
   - Added updateTableHeaders() function that toggles has-rows class
   - Headers hide by default, show only when table has rows
   - Function called on page load and after all add/remove operations
   - Works across all browsers without modern CSS requirements

Changed files:
- includes/class-wc-tpp-product-meta.php - Fixed WooCommerce hook
- assets/css/admin.css - Class-based header visibility
- assets/js/admin.js - Added updateTableHeaders() and parent handlers

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

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

assets/css/admin.css

@@ -112,10 +112,16 @@
 }
 
 /* Hide table headers when there are no pricing rules */
-/* Use :has() pseudo-class to check if tbody is empty */
-.wc-tpp-tiers-table:has(tbody.wc-tpp-tiers-container:empty) thead,
-.wc-tpp-packages-table:has(tbody.wc-tpp-packages-container:empty) thead {
-    display: none !important;
+/* Default: hide headers initially, JavaScript will show them when rows are added */
+.wc-tpp-tiers-table thead,
+.wc-tpp-packages-table thead {
+    display: none;
+}
+
+/* Show headers when table has pricing rows */
+.wc-tpp-tiers-table.has-rows thead,
+.wc-tpp-packages-table.has-rows thead {
+    display: table-header-group !important;
 }
 
 /* Checkbox styling improvements */