* Add _parse_link helper validating both node_id (str) and slot_idx (int,
rejecting bool) so malformed API JSON (e.g. ['n1', '0']) degrades to
AnyType instead of crashing with TypeError.
* Add slot_idx type guards in resolve_output_type and is_output_list.
* Extract _get_class_def_for_node helper to dedupe node/class lookup
across resolve_output_type, is_output_list, get_declared_slot_io_type.
* register_dynamic_input_func now detects 5-argument legacy callables
via inspect.signature and silently wraps them; preserves backward
compatibility for any custom node that registered its own dynamic
input expansion against the pre-live_input_types signature.
* Tests: malformed link (str slot idx, wrong arity), bad slot type
directly to resolve_output_type, non-string class_type. Tests for
the legacy 5-arg shim and the modern 6-arg passthrough, including
callables with uninspectable signatures.
Amp-Thread-ID: https://ampcode.com/threads/T-019e8568-f382-743d-a97f-0de3ff29d501
Co-authored-by: Amp <amp@ampcode.com>
