feat: Add PHP inheritance extraction and improve method call handling

Addresses PHP's base_clause syntax for class inheritance (extends) and implements clause for interface implementation. Adds trait_declaration support and separates property_declaration into fieldTypes. Improves PHP method call extraction by handling member_call_expression and scoped_call_expression with proper receiver name processing, including $ prefix stripping and self/this/parent/static receiver filtering.

__tests__/extraction.test.ts

@@ -815,6 +815,37 @@ class UserController
     expect(classNode).toBeDefined();
     expect(classNode?.name).toBe('UserController');
   });
+
+  it('should extract class inheritance (extends) and interface implementation', () => {
+    const code = `<?php
+
+class ChildController extends BaseController implements Serializable, JsonSerializable
+{
+    public function serialize(): string
+    {
+        return json_encode($this);
+    }
+}
+`;
+    const result = extractFromSource('ChildController.php', code);
+
+    const classNode = result.nodes.find((n) => n.kind === 'class');
+    expect(classNode).toBeDefined();
+    expect(classNode?.name).toBe('ChildController');
+
+    const extendsRef = result.unresolvedReferences.find(
+      (r) => r.referenceKind === 'extends'
+    );
+    expect(extendsRef).toBeDefined();
+    expect(extendsRef?.referenceName).toBe('BaseController');
+
+    const implementsRefs = result.unresolvedReferences.filter(
+      (r) => r.referenceKind === 'implements'
+    );
+    expect(implementsRefs.length).toBe(2);
+    expect(implementsRefs.map((r) => r.referenceName)).toContain('Serializable');
+    expect(implementsRefs.map((r) => r.referenceName)).toContain('JsonSerializable');
+  });
 });
 
 describe('Swift Extraction', () => {