Move desktop and e2e into examples/ directory

- desktop/ → examples/django-react-desktop-app/
- e2e/ → examples/django-react-site/
- example/ → examples/django-react-site/backend/
- Update Dockerfile.test, Makefile, playwright config, and
  django.config.mjs path references

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

examples/django-react-site/harness/django.config.mjs

@@ -0,0 +1,22 @@
+import path from 'path'
+import { fileURLToPath } from 'url'
+
+const __dirname = path.dirname(fileURLToPath(import.meta.url))
+const root = path.resolve(__dirname, '../../..')
+
+export default {
+    projectId: 'e2e-harness',
+
+    source: {
+        django: {
+            managePath: path.join(root, 'examples/django-react-site/backend/manage.py'),
+            command: [path.join(root, 'django/.venv/bin/python')],
+            env: {
+                PYTHONPATH: `${path.join(root, 'django/src')}:${path.join(root, 'examples/django-react-site/backend')}`,
+                DJANGO_SETTINGS_MODULE: 'testapp.settings',
+            },
+        },
+    },
+
+    output: 'src/api/generated.ts',
+}