* 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
- Make sure we're always using regex with timeouts for user controlled data
- Adds rate limiting to the token endpoint (configurable)
- Signs the classifier pickle file with the SECRET_KEY and refuse to load one which doesn't verify.
- Require the user to set a secret key, instead of falling back to our old hard coded one