fix(union): complete downstream container handling

__tests__/context.test.ts

@@ -135,10 +135,16 @@ export function validateEmail(email: string): boolean {
 `
     );
 
+    fs.writeFileSync(
+      path.join(srcDir, 'callback_ops.c'),
+      `union CallbackOps { int (*run)(int); };
+`
+    );
+
     // Initialize CodeGraph
     cg = CodeGraph.initSync(testDir, {
       config: {
-        include: ['**/*.ts'],
+        include: ['**/*.ts', '**/*.c'],
         exclude: [],
       },
     });
@@ -194,6 +200,15 @@ export function validateEmail(email: string): boolean {
       ).toBe(true);
     });
 
+    it('includes union definitions in the default context search', async () => {
+      const result = await cg.findRelevantContext('CallbackOps');
+      const union = [...result.nodes.values()].find(
+        (node) => node.kind === 'union' && node.name === 'CallbackOps'
+      );
+
+      expect(union).toBeDefined();
+    });
+
     it('should include edges in the result', async () => {
       const result = await cg.findRelevantContext('checkout', {
         traversalDepth: 2,