Upgrade PHPStan to 2.x and raise analysis level from 6 to 10

- Bump phpstan/phpstan ^2.0 and szepeviktor/phpstan-wordpress ^2.0
- Move the analysis level into phpstan.neon (single source) and raise it to 10
- Add Val, a runtime coercion helper that narrows untyped WordPress boundary
  values (wpdb rows, REST params, superglobals, options) with explicit checks
  instead of blind casts, plus unit tests
- Type value-object fromRow() params as stdClass (what wpdb returns) and map
  columns through Val so unexpected shapes degrade safely
- Use %i identifier placeholders for table names in all wpdb::prepare() calls
  so every query string is a literal and identifiers are escaped by WordPress;
  raises the minimum WordPress version to 6.2 where %i was introduced
- Guard wpdb::prepare() null result before wpdb::query() in updateTax()
- Fix nullable get_permalink()/strtotime() handling, list types at REST and
  capability call sites, dead null-coalescing on checked superglobals, and
  narrow get_users() results before mapping
- Register Val method names with the ValidatedSanitizedInput sniff so it
  validates the real sanitizer around each superglobal read
- Update repository unit tests for the %i placeholder arguments

Co-Authored-By: Claude Fable 5 <[email protected]>

src/Auth/RegistrationController.php

@@ -3,6 +3,8 @@ declare(strict_types=1);
 
 namespace Unsupervised\Schedular\Auth;
 
+use Unsupervised\Schedular\Val;
+
 class RegistrationController {
 
 	/**
@@ -23,7 +25,7 @@ class RegistrationController {
 		}
 
 		$pendingInvites      = $this->invites->findPending();
-		$registrationPageId  = (int) get_option( self::OPTION_PAGE, 0 );
+		$registrationPageId  = Val::int( get_option( self::OPTION_PAGE, 0 ) );
 		$registrationPageUrl = $registrationPageId > 0 ? (string) get_permalink( $registrationPageId ) : '';
 
 		include USC_PLUGIN_DIR . 'templates/admin/invites.php';
@@ -37,14 +39,14 @@ class RegistrationController {
 	private function handleFormAction(): string {
 		// Nonce is verified by the caller (renderPage) before this method runs.
 		// phpcs:disable WordPress.Security.NonceVerification.Missing
-		$action = sanitize_key( wp_unslash( $_POST['usc_action'] ?? '' ) );
+		$action = sanitize_key( Val::string( wp_unslash( $_POST['usc_action'] ?? '' ) ) );
 
 		if ( 'set_page' === $action ) {
-			update_option( self::OPTION_PAGE, absint( $_POST['registration_page_id'] ?? 0 ) );
+			update_option( self::OPTION_PAGE, absint( Val::int( $_POST['registration_page_id'] ?? 0 ) ) );
 		}
 
 		if ( 'invite' === $action ) {
-			$email = sanitize_email( wp_unslash( $_POST['email'] ?? '' ) );
+			$email = sanitize_email( Val::string( wp_unslash( $_POST['email'] ?? '' ) ) );
 
 			if (
 				is_email( $email )
@@ -66,7 +68,7 @@ class RegistrationController {
 		}
 
 		if ( 'revoke' === $action ) {
-			$inviteId = absint( $_POST['invite_id'] ?? 0 );
+			$inviteId = absint( Val::int( $_POST['invite_id'] ?? 0 ) );
 			if ( $inviteId > 0 ) {
 				$this->invites->revoke( $inviteId );
 			}
@@ -80,7 +82,7 @@ class RegistrationController {
 	 * Build the registration URL for a raw invite token.
 	 */
 	private function registrationLink( string $rawToken ): string {
-		$pageId   = (int) get_option( self::OPTION_PAGE, 0 );
+		$pageId   = Val::int( get_option( self::OPTION_PAGE, 0 ) );
 		$linkBase = $pageId > 0 ? (string) get_permalink( $pageId ) : '';
 
 		return add_query_arg( 'us_invite', rawurlencode( $rawToken ), '' !== $linkBase ? $linkBase : home_url( '/' ) );