Add phpBinary to DebugServer options array shape

PHPStan flagged the new $this->options['phpBinary'] ?? '' lookup because
the @param array shape on DebugServer::__construct didn't declare
`phpBinary`. Without the shape entry PHPStan inferred the offset as
absent and folded the ?? '' to a literal '', triggering both an
"offset does not exist" error and a "strict comparison '' !== '' always
false" follow-up at each of the two new call sites.

Add `phpBinary?: string` to the array shape so PHPStan agrees with the
runtime behavior. No code change.

Author: koriym

src/DebugServer.php

@@ -166,7 +166,7 @@ final class DebugServer
     /** @var array{id: string, label: string, file: string, line: int, condition?: string}|null */
     private array|null $activeBreakpoint = null;
 
-    /** @param array{command?: list<string>, context?: string, breakpoint?: string, steps?: int, connectionTimeout?: float, executionTimeout?: float, traceOnly?: bool, maxSteps?: int, jsonOutput?: bool, breakpoints?: list<array{file: string, line: int|string, condition?: string}>, readTimeout?: float, watches?: list<string>, pretty?: bool, maxValueBytes?: int|null, maxDepth?: int|null} $options */
+    /** @param array{command?: list<string>, context?: string, breakpoint?: string, steps?: int, connectionTimeout?: float, executionTimeout?: float, traceOnly?: bool, maxSteps?: int, jsonOutput?: bool, breakpoints?: list<array{file: string, line: int|string, condition?: string}>, readTimeout?: float, watches?: list<string>, pretty?: bool, maxValueBytes?: int|null, maxDepth?: int|null, phpBinary?: string} $options */
     public function __construct(
         private readonly string $targetScript,
         private readonly int $debugPort,