feat(search): draw real node box from disabled-pack source

Click a node name (or 'Draw this node') in the mirror-search palette to render
an imitation ComfyUI node box with its real input sockets, widget defaults, and
output sockets. Since disabled packs aren't loaded (no /object_info entry), a
new read-only backend module (node_introspect.py) AST-parses the pack on disk —
never importing or executing it — to recover INPUT_TYPES / RETURN_TYPES from a
literal NODE_CLASS_MAPPINGS. New GET /nodes-stats/node-schema endpoint resolves
the disabled pack dir (handling @version suffixes / case) and returns the schema
off the event loop. Frontend lazily fetches + caches per node, renders sockets
vs widgets with type-colored dots, and falls back to a placeholder for packs
that build their node list dynamically.

End-to-end against the live install: 67/68 disabled packs resolve on disk, ~92%
of nodes render a real box, the rest fall back cleanly. Adds 7 parser unit
tests (36 total green). Bump to 1.6.0.

tests/test_node_introspect.py

@@ -0,0 +1,131 @@
+import os
+import sys
+from unittest.mock import MagicMock
+
+import node_introspect as ni
+
+
+_SAMPLE = '''
+import folder_paths
+
+
+class MyCoolNode:
+    @classmethod
+    def INPUT_TYPES(cls):
+        return {
+            "required": {
+                "image": ("IMAGE",),
+                "model": ("MODEL",),
+                "strength": ("FLOAT", {"default": 1.5, "min": 0.0}),
+                "mode": (["fast", "slow"], {"default": "slow"}),
+                "ckpt": (folder_paths.get_filename_list("checkpoints"),),
+            },
+            "optional": {
+                "mask": ("MASK",),
+            },
+        }
+
+    RETURN_TYPES = ("IMAGE", "LATENT")
+    RETURN_NAMES = ("out_image", "out_latent")
+    CATEGORY = "testing/cool"
+    FUNCTION = "run"
+
+    def run(self, image, model, strength, mode, ckpt, mask=None):
+        return (image, None)
+
+
+class DynamicNode:
+    @classmethod
+    def INPUT_TYPES(cls):
+        d = {"required": {}}
+        return d
+    RETURN_TYPES = ("STRING",)
+
+
+NODE_CLASS_MAPPINGS = {"My Cool Node": MyCoolNode}
+NODE_CLASS_MAPPINGS.update({"Dynamic": DynamicNode})
+NODE_DISPLAY_NAME_MAPPINGS = {"My Cool Node": "My Cool Node ✨"}
+'''
+
+
+def _write_pack(tmp_path, body=_SAMPLE, name="nodes.py"):
+    ni._INDEX_CACHE.clear()
+    f = tmp_path / name
+    f.write_text(body)
+    return str(tmp_path)
+
+
+def test_inputs_sockets_widgets_and_defaults(tmp_path):
+    pack = _write_pack(tmp_path)
+    s = ni.get_node_schema("My Cool Node", pack)
+    assert s["parseable"] is True
+    assert s["display_name"] == "My Cool Node ✨"
+    assert s["category"] == "testing/cool"
+    by = {i["name"]: i for i in s["inputs"]}
+
+    # custom types are sockets
+    assert by["image"]["type"] == "IMAGE" and by["image"]["widget"] is False
+    assert by["model"]["type"] == "MODEL" and by["model"]["widget"] is False
+    # primitives + combos are widgets, with defaults
+    assert by["strength"]["widget"] is True and by["strength"]["default"] == 1.5
+    assert by["mode"]["type"] == "COMBO" and by["mode"]["options"] == ["fast", "slow"]
+    assert by["mode"]["default"] == "slow"
+    # folder_paths.get_filename_list(...) -> dynamic combo widget, options unknown
+    assert by["ckpt"]["type"] == "COMBO" and by["ckpt"]["widget"] is True
+    assert by["ckpt"]["options"] is None
+    # optional inputs are flagged
+    assert by["mask"]["required"] is False and by["image"]["required"] is True
+
+
+def test_outputs_use_return_names(tmp_path):
+    pack = _write_pack(tmp_path)
+    s = ni.get_node_schema("My Cool Node", pack)
+    assert [(o["name"], o["type"]) for o in s["outputs"]] == [
+        ("out_image", "IMAGE"),
+        ("out_latent", "LATENT"),
+    ]
+
+
+def test_mapping_update_call_is_merged(tmp_path):
+    pack = _write_pack(tmp_path)
+    s = ni.get_node_schema("Dynamic", pack)
+    assert s["parseable"] is True
+    assert s["outputs"] == [{"name": "STRING", "type": "STRING"}]
+    assert s["inputs"] == []
+
+
+def test_unknown_class_type_not_parseable(tmp_path):
+    pack = _write_pack(tmp_path)
+    s = ni.get_node_schema("Nope", pack)
+    assert s["parseable"] is False
+    assert s["reason"] == "dynamic_mapping"
+
+
+def test_no_mapping_reason(tmp_path):
+    pack = _write_pack(tmp_path, body="class A:\n    RETURN_TYPES = ('X',)\n")
+    s = ni.get_node_schema("A", pack)
+    # class_type falls back to the class name even without NODE_CLASS_MAPPINGS
+    assert s["parseable"] is True
+    s2 = ni.get_node_schema("Missing", pack)
+    assert s2["parseable"] is False and s2["reason"] == "no_mapping"
+
+
+def test_find_disabled_pack_path_strips_version_and_case(tmp_path, monkeypatch):
+    cn = tmp_path / "custom_nodes"
+    disabled = cn / ".disabled"
+    disabled.mkdir(parents=True)
+    (disabled / "ComfyMath@nightly").mkdir()
+
+    fp = MagicMock()
+    fp.get_folder_paths.return_value = [str(cn)]
+    monkeypatch.setitem(sys.modules, "folder_paths", fp)
+
+    found = ni.find_disabled_pack_path("comfymath")
+    assert found == os.path.join(str(disabled), "ComfyMath@nightly")
+    assert ni.find_disabled_pack_path("not-there") is None
+
+
+def test_find_disabled_pack_path_rejects_traversal(tmp_path):
+    assert ni.find_disabled_pack_path("../evil") is None
+    assert ni.find_disabled_pack_path("a/b") is None
+    assert ni.find_disabled_pack_path("") is None