Tags remaining live-but-deprecated routes so every call logs a warning,
giving visibility before the next round of removals.
- registry.py: add DeprecationParams to importing and user routers
- api.py: add DeprecationParams to /request_jwt and /temp_token individually
- user.py: inherits deprecation warning via registry router-level dependency
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>