The C directoryListCallback now directly builds a Wren list using wrenSetSlotNewList and wrenInsertInList, eliminating the temporary byte buffer that required manual splitting in Wren. The Wren side is simplified to a single return of the scheduler result. Additionally, the wrenCall and wrenCaptureValue functions are hardened: wrenCall discards extra temporary slots and calls with arity 0, wrenCaptureValue properly roots/unroots object values during handle creation, and the debug stack trace printer skips stub functions with NULL module pointers. A new test case verifies that wrenCall correctly ignores extra temporary slots on the stack.