Split the monolithic management.py (1988 lines) into 4 focused modules:
- management.py: Server status, user sessions, shared helpers (~520 lines)
- passwords.py: App password provisioning for BasicAuth mode (~300 lines)
- webhooks.py: Webhook registration management (~290 lines)
- visualization.py: Search and PDF preview endpoints (~810 lines)
Backward compatibility maintained via __init__.py re-exports.
Updated test imports to use new module paths.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>