Support SQLite through the SQLite Database Integration plugin #527

I'd like to run Pollora without a MySQL server: locally, in CI, or for a demo. Laravel already defaults to SQLite, and WordPress has the official SQLite Database Integration plugin, so I tried to combine both.

Today Pollora only loads WordPress on the mysql driver (QueryTrait::isDatabaseConfigured()), so with DB_CONNECTION=sqlite every page returns the 503 "Pollora is not set up yet".

I got it working with three changes (framework v13.38.1, WordPress 7.1.3, plugin 3.1.1):

1. Accept sqlite in isDatabaseConfigured():

if ($config['driver'] === 'sqlite') {
    return file_exists($config['database']);
}

2. Load the plugin from public/content/db.php instead of WordPressDatabase:

define('DB_ENGINE', 'sqlite');
define('DB_PATH', config('database.connections.sqlite.database'));

require_once __DIR__.'/plugins/sqlite-database-integration/wp-includes/sqlite/db.php';

3. Give the sqlite connection the same pf_ prefix as mysql in config/database.php. Without it, requests served by Laravel use the default connection's prefix (empty), while wp-login.php and wp-admin use the mysql one from wp-config.php, and the admin redirects to install.php. Reading the default connection's prefix in wp-config.php would probably be cleaner.

With that, pollora:install and pollora:doctor pass, and the front end and the admin (login, editing, settings, REST) all work on one database/database.sqlite shared with Laravel.

A few other places assume MySQL: SetupRequiredResponse, the installer, and the docs, which say SQLite is not supported while the skeleton README lists it. Some plugins may not work with the SQLite plugin, so MySQL would stay the choice for production.

Would you be open to this as an opt-in? If so, I'm happy to open PRs on the framework and the skeleton.