Dr.Lt.Data af96d9812d
feat(security): add System User protection with __ prefix (#10966)
* feat(security): add System User protection with `__` prefix

Add protected namespace for custom nodes to store sensitive data
(API keys, licenses) that cannot be accessed via HTTP endpoints.

Key changes:
- New API: get_system_user_directory() for internal access
- New API: get_public_user_directory() with structural blocking
- 3-layer defense: header validation, path blocking, creation prevention
- 54 tests covering security, edge cases, and backward compatibility

System Users use `__` prefix (e.g., __system, __cache) following
Python's private member convention. They exist in user_directory/
but are completely blocked from /userdata HTTP endpoints.

* style: remove unused imports
2025-11-28 21:28:42 -05:00
..