Add finalizer invocation for foreign objects during garbage collection by calling wrenFinalizeForeign in wrenFreeObj. Expose wrenCollectGarbage as a public API function and update internal calls accordingly. Ensure the "<finalize>" symbol is always registered in the symbol table even when no finalizer is provided. Add test fixtures for Resource class with finalizer and Api.gc/Api.finalized methods to verify finalization behavior across multiple GC cycles.