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/Availability/AvailabilitySlot.php

@@ -3,6 +3,8 @@ declare(strict_types=1);
 
 namespace Unsupervised\Schedular\Availability;
 
+use Unsupervised\Schedular\Val;
+
 class AvailabilitySlot {
 
 	public function __construct(
@@ -35,16 +37,16 @@ class AvailabilitySlot {
 		return null;
 	}
 
-	public static function fromRow( object $row ): self {
+	public static function fromRow( \stdClass $row ): self {
 		return new self(
-			instructorId:    (int) $row->instructor_id,
-			startDt:         $row->start_dt,
-			endDt:           $row->end_dt,
-			durationMinutes: (int) $row->duration_minutes,
-			offeringId:      null !== $row->offering_id ? (int) $row->offering_id : null,
-			isBooked:        (bool) $row->is_booked,
-			recurrenceGroup: null !== $row->recurrence_group ? (int) $row->recurrence_group : null,
-			id:              (int) $row->id,
+			instructorId:    Val::int( $row->instructor_id ),
+			startDt:         Val::string( $row->start_dt ),
+			endDt:           Val::string( $row->end_dt ),
+			durationMinutes: Val::int( $row->duration_minutes ),
+			offeringId:      Val::intOrNull( $row->offering_id ),
+			isBooked:        Val::bool( $row->is_booked ),
+			recurrenceGroup: Val::intOrNull( $row->recurrence_group ),
+			id:              Val::int( $row->id ),
 		);
 	}