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/Payment/Payment.php

@@ -3,6 +3,8 @@ declare(strict_types=1);
 
 namespace Unsupervised\Schedular\Payment;
 
+use Unsupervised\Schedular\Val;
+
 class Payment {
 
 	public const METHOD_CARD      = 'card';
@@ -50,24 +52,24 @@ class Payment {
 		public readonly ?int $id = null,
 	) {}
 
-	public static function fromRow( object $row ): self {
+	public static function fromRow( \stdClass $row ): self {
 		return new self(
-			studentId:             (int) $row->student_id,
-			instructorId:          (int) $row->instructor_id,
-			registrationType:      $row->registration_type,
-			registrationId:        (int) $row->registration_id,
-			amount:                (float) $row->amount,
-			currency:              $row->currency,
-			method:                $row->method,
-			status:                $row->status,
-			taxRate:               (float) $row->tax_rate,
-			taxAmount:             (float) $row->tax_amount,
-			etransferEmail:        $row->etransfer_email,
-			stripePaymentIntentId: $row->stripe_payment_intent_id,
-			receiptNumber:         $row->receipt_number,
-			receiptSentAt:         $row->receipt_sent_at,
-			paidAt:                $row->paid_at,
-			id:                    (int) $row->id,
+			studentId:             Val::int( $row->student_id ),
+			instructorId:          Val::int( $row->instructor_id ),
+			registrationType:      Val::string( $row->registration_type ),
+			registrationId:        Val::int( $row->registration_id ),
+			amount:                Val::float( $row->amount ),
+			currency:              Val::string( $row->currency ),
+			method:                Val::string( $row->method ),
+			status:                Val::string( $row->status ),
+			taxRate:               Val::float( $row->tax_rate ),
+			taxAmount:             Val::float( $row->tax_amount ),
+			etransferEmail:        Val::stringOrNull( $row->etransfer_email ),
+			stripePaymentIntentId: Val::stringOrNull( $row->stripe_payment_intent_id ),
+			receiptNumber:         Val::stringOrNull( $row->receipt_number ),
+			receiptSentAt:         Val::stringOrNull( $row->receipt_sent_at ),
+			paidAt:                Val::stringOrNull( $row->paid_at ),
+			id:                    Val::int( $row->id ),
 		);
 	}