Release version 1.1.17 - Array duplicate prevention

Fixed persistent duplicate settings page by adding array-level duplicate
detection in addition to singleton pattern from v1.1.16.

Root Cause:
- WooCommerce calls woocommerce_get_settings_pages filter multiple times
- Even with singleton pattern, each filter call added settings instance to array
- Singleton prevented multiple class instances but not multiple array entries

Fixes:
- Settings page rendering twice despite singleton pattern in v1.1.16
- Filter adding same settings instance to array on repeated calls

Changes:
- Added duplicate detection loop in add_settings_page() before array append
- Uses strict comparison (===) to check if instance already in array
- Returns early if settings page already present, preventing duplicate

Technical Details:
- foreach loop iterates through existing $settings array
- Compares each element against cached self::$settings_instance
- Only appends to array if instance not found
- Complements singleton pattern with array-level protection
- Handles WooCommerce calling filter multiple times during page load

Updated Files:
- includes/class-wc-tpp-admin.php (added duplicate check in filter)
- wc-tier-and-package-prices.php (version 1.1.17)
- composer.json (version 1.1.17)
- CHANGELOG.md (v1.1.17 section)

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

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

CHANGELOG.md

@@ -5,6 +5,26 @@ All notable changes to WooCommerce Tier and Package Prices will be documented in
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [1.1.17] - 2025-12-22
+
+### Fixed
+
+- Settings page still rendering twice despite singleton pattern in v1.1.16
+- Filter adding settings instance to array multiple times when called repeatedly
+
+### Changed
+
+- Added duplicate detection in `add_settings_page()` filter method
+- Filter now checks if settings instance already exists in array before adding
+
+### Technical Details
+
+- Added foreach loop to check existing settings pages in array
+- Uses strict comparison (`===`) to detect if exact instance already present
+- Returns early if settings instance found, preventing duplicate array entries
+- Complements singleton pattern from v1.1.16 with array-level duplicate prevention
+- Handles edge case where WooCommerce calls filter multiple times
+
 ## [1.1.16] - 2025-12-22
 
 ### Fixed