Include unsealed extras in ConstantArrayTypeBuilder degraded-array form

`ConstantArrayTypeBuilder::getArray()` in the degrade-to-general-array
branch builds `new ArrayType(union($keyTypes), union($valueTypes))`
from the explicit slots only — the unsealed extras' key/value
contribution was silently dropped.

Union the unsealed key/value into the degraded `ArrayType`'s key and
value unions when the builder carries real extras. Fixes shuffleArray
(and any other call site that round-trips through
`degradeToGeneralArray()`) on unsealed sources, where the unsealed
value type now reaches the final list/array form.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: ondrejmirtes

src/Type/Constant/ConstantArrayTypeBuilder.php

@@ -473,8 +473,21 @@ public function getArray(): Type
 			$itemTypes = $this->valueTypes;
 		}
 
+		$keyTypesForArray = $this->keyTypes;
+		// Real unsealed extras describe additional key/value pairs that
+		// belong in the degraded `ArrayType`'s key/value unions too —
+		// otherwise the degraded type silently drops them.
+		if ($this->unsealed !== null) {
+			[$unsealedKey, $unsealedValue] = $this->unsealed;
+			$isExplicitNever = $unsealedKey instanceof NeverType && $unsealedKey->isExplicit();
+			if (!$isExplicitNever) {
+				$keyTypesForArray[] = $unsealedKey;
+				$itemTypes[] = $unsealedValue;
+			}
+		}
+
 		$array = new ArrayType(
-			TypeCombinator::union(...$this->keyTypes),
+			TypeCombinator::union(...$keyTypesForArray),
 			TypeCombinator::union(...$itemTypes),
 		);
 

tests/PHPStan/Analyser/nsrt/unsealed-derivations.php

@@ -496,6 +496,24 @@ public function chunkPreservingKeys(array $arr): void
 
 }
 
+class ShuffleArray
+{
+
+	/**
+	 * @param array{a: 1, b: 2, ...<int, string>} $arr
+	 */
+	public function shufflePreservesUnsealedValues(array $arr): void
+	{
+		// `shuffle` reorders + reindexes. Through `getValuesArray()`
+		// the source's unsealed value type contributes to the result's
+		// value union — the final degraded list type includes `string`
+		// alongside the explicit values `1` and `2`.
+		shuffle($arr);
+		assertType('non-empty-list<1|2|string>', $arr);
+	}
+
+}
+
 class CountNarrowing
 {