DynamicSlot: typed option dispatch driven by TypeResolver

Replaces the old connected/unconnected fixed-child DynamicSlot with a
type-keyed option list. Each Option declares a 'when' condition (None,
io.AnyType, a single ComfyType, a list, or a MultiType.Input) and the
child inputs revealed when that condition matches the slot's resolved
upstream type.

Selection happens at schema-finalization time using live_input_types
computed by TypeResolver, so API-only workflows (no frontend) get the
same expansion the UI would.

- _io.py: redesign DynamicSlot.Input / Option; auto-derive slotType as
  the union of all non-None when sets; expose it via as_dict so the
  frontend knows what types are accepted; the class io_type stays
  COMFY_DYNAMICSLOT_V3 as the parse-time dispatch tag.
- type_resolver.py: return the auto-derived _slot_io_type for
  DynamicSlot.Input; document the AnyType (*) limitation.
- execution.py: validate links into a DynamicSlot against slotType,
  not the dispatch tag COMFY_DYNAMICSLOT_V3.
- tests: new test_dynamic_slot.py + regression coverage in
  test_type_resolver.py.

Amp-Thread-ID: https://ampcode.com/threads/T-019e8568-f382-743d-a97f-0de3ff29d501
Co-authored-by: Amp <amp@ampcode.com>

execution.py

@@ -926,7 +926,14 @@ async def validate_inputs(prompt_id, prompt, item, validated, visiting=None, typ
             # frontend-injected type metadata get the same answer as the UI.
             received_type = type_resolver.resolve_output_type(o_id, val[1])
             received_types[x] = received_type
-            if 'input_types' not in validate_function_inputs and not validate_node_input(received_type, input_type):
+            # DynamicSlot publishes its accepted connection types via the
+            # `slotType` field (auto-derived union of option `when` types).
+            # The declared input_type ("COMFY_DYNAMICSLOT_V3") is just the
+            # dispatch tag; validate against slotType instead.
+            effective_input_type = input_type
+            if input_type == _io.DynamicSlot.io_type and isinstance(extra_info, dict):
+                effective_input_type = extra_info.get("slotType", input_type)
+            if 'input_types' not in validate_function_inputs and not validate_node_input(received_type, effective_input_type):
                 details = f"{x}, received_type({received_type}) mismatch input_type({input_type})"
                 error = {
                     "type": "return_type_mismatch",