Release version 1.1.0 - Package quantity restriction feature

Added comprehensive package quantity restriction functionality that allows
limiting product purchases to predefined package sizes only.

Features:
- Global setting to enable package quantity restrictions
- Per-product override for quantity restrictions
- Automatic hiding of quantity input field when restricted
- Frontend validation with package selection UI
- Server-side cart validation
- User-friendly error messages
- Complete translations for all supported languages

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

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

templates/frontend/package-pricing-display.twig

@@ -3,13 +3,17 @@
  #
  # @package WC_Tier_Package_Prices
  # @var array packages
+ # @var bool restrict_to_packages
  #}
-<div class="wc-tpp-package-pricing-table">
+<div class="wc-tpp-package-pricing-table{% if restrict_to_packages %} wc-tpp-restricted-mode{% endif %}">
     <h3>{{ 'Package Deals'|__('wc-tier-package-prices') }}</h3>
+    {% if restrict_to_packages %}
+        <p class="wc-tpp-restriction-notice">{{ 'Choose a package size below'|__('wc-tier-package-prices') }}</p>
+    {% endif %}
     <div class="wc-tpp-packages">
         {% for index, package in packages %}
             {% set price_per_unit = package.qty > 0 ? package.price / package.qty : 0 %}
-            <div class="wc-tpp-package" data-qty="{{ package.qty|esc_attr }}" data-price="{{ package.price|esc_attr }}">
+            <div class="wc-tpp-package{% if restrict_to_packages %} wc-tpp-package-selectable{% endif %}" data-qty="{{ package.qty|esc_attr }}" data-price="{{ package.price|esc_attr }}">
                 <div class="wc-tpp-package-header">
                     {% if package.label is not empty %}
                         <h4>{{ package.label|esc_html }}</h4>