Version v2.6.2

chore(release): Bump version to 2.6.2

This commit prepares the plugin for a new maintenance release, addressing a critical bug in the self-hosted updater that caused a "plugin not found" error.

The version number has been incremented to 2.6.2 in all relevant files (`wp-genai-tools.php`, `class-diffyweb-genai-tools.php`, and `info.json`).

The changelog in `info.json` has also been updated to reflect the latest fix, which corrects the updater's slug generation and implements the `plugins_api` filter to ensure updates and changelogs work reliably, regardless of the plugin's installation directory name.