Core: uninstall from uninstall.php instead of register_uninstall_hook() - #1078

What

Core::init() no longer calls register_uninstall_hook(). A new uninstall.php in the plugin root runs the same cleanup:

defined( 'WP_UNINSTALL_PLUGIN' ) || exit();
require_once __DIR__ . '/litespeed-cache.php';
\LiteSpeed\Activation::uninstall_litespeed_cache();

Why

register_uninstall_hook() reads the uninstall_plugins option every time it is called. Core keeps that option out of autoload on purpose (the comment in wp-includes/plugin.php says "Emphasis should be put on using the 'uninstall.php' way"). Since the call sits in Core::init(), every request, including every uncached front-end page view, paid one extra database query for it. The Plugin Handbook lists uninstall.php as the second method, and the user notes on the function reference point to the per-request cost (Trac #31792).

Behaviour on uninstall stays the same: when uninstall.php exists, uninstall_plugin() removes the old uninstall_plugins entry, defines WP_UNINSTALL_PLUGIN and includes the file. The file includes the main plugin file first, as core did for the hook, so Activation::uninstall_litespeed_cache() finds the autoloader and constants.

Tested

Real WordPress 7.1.3 (SQLite), PHP 8.4, with and without this branch on the same database copy:

vendor/bin/phpcs --standard=phpcs.ruleset.xml uninstall.php src/core.cls.php reports nothing.