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/StudentSchedule.php

@@ -3,6 +3,8 @@ declare(strict_types=1);
 
 namespace Unsupervised\Schedular\Auth;
 
+use Unsupervised\Schedular\Val;
+
 /**
  * Pure helper for splitting a student's dated rows into upcoming and past.
  */
@@ -21,7 +23,7 @@ class StudentSchedule {
 		$past     = [];
 
 		foreach ( $rows as $row ) {
-			$start = (string) ( $row['start_dt'] ?? '' );
+			$start = Val::string( $row['start_dt'] ?? '' );
 			if ( '' !== $start && $start >= $now ) {
 				$upcoming[] = $row;
 			} else {
@@ -29,12 +31,12 @@ class StudentSchedule {
 			}
 		}
 
-		usort( $upcoming, static fn( array $a, array $b ): int => strcmp( (string) ( $a['start_dt'] ?? '' ), (string) ( $b['start_dt'] ?? '' ) ) );
-		usort( $past, static fn( array $a, array $b ): int => strcmp( (string) ( $b['start_dt'] ?? '' ), (string) ( $a['start_dt'] ?? '' ) ) );
+		usort( $upcoming, static fn( array $a, array $b ): int => strcmp( Val::string( $a['start_dt'] ?? '' ), Val::string( $b['start_dt'] ?? '' ) ) );
+		usort( $past, static fn( array $a, array $b ): int => strcmp( Val::string( $b['start_dt'] ?? '' ), Val::string( $a['start_dt'] ?? '' ) ) );
 
 		return [
-			'upcoming' => array_values( $upcoming ),
-			'past'     => array_values( $past ),
+			'upcoming' => $upcoming,
+			'past'     => $past,
 		];
 	}
 }