[cv6] Letter Index 1.3.0

Release 1.3.0

• Multi-Alphabet Provider Architecture: You can now choose the alphabet used for grouping and filtering per forum and Resource Manager category in the AdminCP.
• Supported Alphabets Out-of-the-Box: Includes Latin (A–Z), Greek (Α–Ω), Cyrillic (А–Я), Hebrew (א–ת), and Arabic (ا–ي) via cv6/Core's Alphabet repository.
• Letter Normalization & Diacritics Handling: Intelligently normalizes accented and regional variant characters (such as Greek Tonos vowels, Cyrillic South Slavic/Abkhazian ligatures, Arabic Alif/Ya and Perso-Arabic letters, and Hebrew Sofit final forms) into their base alphabet tabs.
• RTL Script Support: Automatic right-to-left layout for Hebrew and Arabic index tab bars.
• Extensible Architecture: Developers can easily register custom alphabets using the cv6_core_index_alphabets code event or class extensions on \cv6\Core\Repository\Alphabet.
• Core Dependency Alignment: Updated minimum required cv6/Core version to 1.5.0+ (ID: 1050070).

• Listener: Added missing column existence guard in addonPostInstall for xf_rm_category.
• Forum Entity: Parameterized fetchLetterCounter() SQL query with prepared statement parameter (node_id = ?).
• Setup: Removed unused stub methods.
  [']Wording changed to letter to avoid confusion with a another AddOn,.

• Works now with XenFro 2.3.8+

XF 2.3 Version only

Forum and Category Settings are now divided into two options.
Enable indexing
Display Index

Added a Index Widget.

The indexing needs to be enabled that the widget is shown.

Updated the addon code to work with xf 2.3