Release version 1.2.6 - Critical bugfixes for v1.2.5 features

Fixed two critical issues that prevented v1.2.5 features from working:

1. Parent Product Pricing Forms Not Visible (Critical)
   - Variable products were missing admin UI for parent pricing configuration
   - v1.2.5 implemented backend logic but forgot the admin forms
   - Added add_variable_parent_pricing_fields() method
   - Modified existing methods to skip variable products (simple only)
   - Parent pricing now fully functional with matching UI

2. Table Headers Not Hiding When Empty
   - CSS sibling selector ~ doesn't work when thead comes before tbody
   - Removed incorrect selector, kept only :has() pseudo-class
   - Added !important flag for proper specificity
   - Modern browser support (Chrome 105+, Firefox 121+, Safari 15.4+)

Changed files:
- includes/class-wc-tpp-product-meta.php - Added parent pricing forms
- assets/css/admin.css - Fixed header hiding CSS
- wc-tier-and-package-prices.php - Version 1.2.6
- composer.json - Version 1.2.6
- CHANGELOG.md - Detailed release notes

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

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

assets/css/admin.css

@@ -112,15 +112,10 @@
 }
 
 /* Hide table headers when there are no pricing rules */
-.wc-tpp-tiers-container:empty ~ thead,
-.wc-tpp-packages-container:empty ~ thead {
-    display: none;
-}
-
-/* Alternative approach: hide thead when tbody is empty (more reliable) */
+/* 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;
+    display: none !important;
 }
 
 /* Checkbox styling improvements */