fix(rust): emit references edges for enum variant field types

Enum variant payload types were silently dropped — `struct_item` and
`trait_item` had type-reference handlers but `enum_item` had none, so the
variant field types were never traversed.

Add an `enum_item` branch that walks
`enum_variant_list -> enum_variant -> ordered_field_declaration_list`
(tuple variants, `Click(Logger)`) and `field_declaration_list` (struct
variants, `Resize { size: Dim }`), emitting a `references` edge from the enum
to each field type. Reuses the same type collection as the struct path. Adds
an enum to the fixture and a regression test.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

graphify/extract.py

@@ -8160,6 +8160,45 @@ def extract_rust(path: Path) -> dict:
                                 if tgt != item_nid:
                                     add_edge(item_nid, tgt, "references",
                                              field.start_point[0] + 1, context=ctx)
+                if t == "enum_item":
+                    # Variant payload types nest under enum_variant_list ->
+                    # enum_variant -> ordered_field_declaration_list (tuple variant,
+                    # `Click(Logger)`) | field_declaration_list (struct variant,
+                    # `Resize { size: Dim }`). Neither was traversed, so every
+                    # enum-variant type reference was silently dropped.
+                    _TYPE_NODES = ("type_identifier", "generic_type",
+                                   "scoped_type_identifier", "reference_type",
+                                   "primitive_type", "tuple_type", "array_type")
+
+                    def _emit_enum_type(type_node, at_line):
+                        if type_node is None:
+                            return
+                        refs2: list[tuple[str, str]] = []
+                        _rust_collect_type_refs(type_node, source, False, refs2)
+                        for ref_name, role in refs2:
+                            ctx = "generic_arg" if role == "generic_arg" else "field"
+                            tgt = ensure_named_node(ref_name, at_line)
+                            if tgt != item_nid:
+                                add_edge(item_nid, tgt, "references", at_line, context=ctx)
+
+                    for c in node.children:
+                        if c.type != "enum_variant_list":
+                            continue
+                        for variant in c.children:
+                            if variant.type != "enum_variant":
+                                continue
+                            vline = variant.start_point[0] + 1
+                            for vc in variant.children:
+                                if vc.type == "ordered_field_declaration_list":
+                                    for tc in vc.children:
+                                        if tc.type in _TYPE_NODES:
+                                            _emit_enum_type(tc, vline)
+                                elif vc.type == "field_declaration_list":
+                                    for field in vc.children:
+                                        if field.type != "field_declaration":
+                                            continue
+                                        type_node = field.child_by_field_name("type")
+                                        _emit_enum_type(type_node, field.start_point[0] + 1)
             return
 
         if t == "impl_item":

tests/fixtures/sample.rs

@@ -51,3 +51,8 @@ impl DataProcessor {
         Result { value: input }
     }
 }
+
+enum GraphEvent {
+    NodeAdded(Graph),
+    Processed { proc: DataProcessor },
+}

tests/test_multilang.py

@@ -346,6 +346,19 @@ def test_rust_supertrait_emits_inherits():
     assert ("Logger", "Processor") in _edge_labels(r, "inherits")
 
 
+def test_rust_enum_variant_references():
+    """Enum variant payload types must emit `references` edges.
+
+    Tuple variants (`Click(T)`) and struct variants (`Resize { x: T }`) nest
+    their field types under enum_variant_list -> enum_variant; that path was
+    never traversed, so every enum-variant type reference was dropped.
+    """
+    r = extract_rust(FIXTURES / "sample.rs")
+    refs = _edge_labels(r, "references")
+    assert ("GraphEvent", "Graph") in refs, "tuple-variant reference missing"
+    assert ("GraphEvent", "DataProcessor") in refs, "struct-variant reference missing"
+
+
 def test_rust_struct_field_emits_field_context():
     r = extract_rust(FIXTURES / "sample.rs")
     assert ("DataProcessor", "Result") in _edge_labels(r, "references", "field")