- Add TestUserContext: tests for UserContext dataclass (creation, to_dict, from_dict)
- Add TestUserContextManager: tests for manager initialization and load
- Add TestAtomicWrites: tests for atomic save with backup rotation
- Add TestMultiUser: tests for multi-user isolation and convenience methods
- Add tmp_users_root and user_context_manager fixtures to conftest.py
- Export UserContext and UserContextManager from __init__.py
Note: Implementation was already done in commit 9bd29a2 as part of 04-02 plan.
This commit adds the tests that should have been part of 04-01 TDD workflow.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>