fix(csharp): emit type references for properties

The C# class-body walker only handled field_declaration, so a
property's type produced no references(field) edge. In idiomatic C#,
auto-properties (`public Widget Main { get; set; }`) — not bare fields
— are the standard way to declare state, so this silently dropped most
of a class's type relationships.

Add a property_declaration branch alongside the field_declaration
handler, guarded the same way (ts_module == tree_sitter_c_sharp,
parent_class_nid set). A property exposes its type on the node directly
(no variable_declaration wrapper), so read it via
child_by_field_name("type") and collect refs with
_csharp_collect_type_refs, mirroring the Java/PHP/Kotlin siblings so
List<Widget> yields both the List field ref and the Widget generic_arg
ref. Only emit when target != parent_class_nid.

graphify/extract.py

@@ -3786,6 +3786,35 @@ def _extract_generic(
                          "references", line, context="field", metadata=metadata)
             return
 
+        if (config.ts_module == "tree_sitter_c_sharp"
+                and t == "property_declaration"
+                and parent_class_nid):
+            # C# auto-properties (`public Widget Main { get; set; }`) are the
+            # idiomatic way to declare state, yet only field_declaration was
+            # handled — so property types produced no references edge. Unlike a
+            # field, a property exposes its type on the node directly (no
+            # variable_declaration wrapper), so read it straight off the `type`
+            # field. Use _csharp_collect_type_refs (like the Java/PHP/Kotlin
+            # siblings) so `List<Widget>` yields both the List field ref and the
+            # Widget generic_arg ref.
+            type_node = node.child_by_field_name("type")
+            if type_node is not None:
+                line = node.start_point[0] + 1
+                refs: list[tuple[str, str, bool, str]] = []
+                _csharp_collect_type_refs(type_node, source, False, refs)
+                for ref_name, role, qualified, qualifier in refs:
+                    ctx = "generic_arg" if role == "generic_arg" else "field"
+                    target_nid = ensure_named_node(ref_name, line)
+                    if target_nid != parent_class_nid:
+                        metadata = {"ref_token": ref_name}
+                        if qualified:
+                            metadata["qualified"] = True
+                        if qualifier:
+                            metadata["ref_qualifier"] = qualifier
+                        add_edge(parent_class_nid, target_nid, "references",
+                                 line, context=ctx, metadata=metadata)
+            return
+
         if (config.ts_module == "tree_sitter_java"
                 and t == "field_declaration"
                 and parent_class_nid):

tests/fixtures/sample.cs

@@ -21,6 +21,10 @@ namespace GraphifyDemo
     {
         private readonly HttpClient _client;
 
+        public Processor Owner { get; set; }
+
+        public List<Processor> Workers { get; set; }
+
         public DataProcessor()
         {
             _client = new HttpClient();

tests/test_languages.py

@@ -542,6 +542,17 @@ def test_csharp_field_type_references_have_field_context():
     ), "DataProcessor field declarations should reference HttpClient with field context"
 
 
+def test_csharp_property_type_references_have_field_context():
+    r = extract_csharp(FIXTURES / "sample.cs")
+    field_refs = _edge_labels(r, "references", "field")
+    # `public Processor Owner { get; set; }` — property type -> field ref.
+    assert ("DataProcessor", "Processor") in field_refs
+    # `public List<Processor> Workers { get; set; }` — the List container -> field.
+    assert ("DataProcessor", "List") in field_refs
+    # ...and the generic argument -> generic_arg.
+    assert ("DataProcessor", "Processor") in _edge_labels(r, "references", "generic_arg")
+
+
 def test_csharp_call_edges_have_call_context():
     r = extract_csharp(FIXTURES / "sample.cs")
     node_by_id = {n["id"]: n["label"] for n in r["nodes"]}