Chore: Improve idle memory via more lazy imports (#14599)

* Chore: Import dateparser lazily so processes that never parse dates skip it

* Chore: Import turbohtml lazily in the mail parser

* Chore: Import lxml lazily in the SVG validator

* Chore: Import paperless_ai.indexing lazily in document tasks

* Chore: Import paperless_ai helpers lazily in views

* Chore: Read the OCRmyPDF sRGB profile on first use instead of at import

* Chore: Import pikepdf and img2pdf lazily so startup does not load them

* Chore: Reuse the initialized Django ASGI application for HTTP routing

src/documents/tests/test_api_document_versions.py

@@ -1110,7 +1110,7 @@ class TestVersionActionPermissions(DirectoriesMixin, APITestCase):
             self.assertEqual(response.status_code, 403)
             with (
                 mock.patch("documents.views.AIConfig") as ai_config,
-                mock.patch("documents.views.stream_chat_with_documents") as chat,
+                mock.patch("paperless_ai.chat.stream_chat_with_documents") as chat,
             ):
                 ai_config.return_value.ai_enabled = True
                 response = self.client.post(