"""
Credential storage backends.

Available backends:
- EnvVarBackend: Environment variables (always available, read-only)
- MacOSKeychainBackend: macOS Keychain Access (requires keyring)
- WindowsCredentialBackend: Windows Credential Manager (requires keyring)
- LegacyFileBackend: Plaintext JSON files (read-only, for backward compat)
"""

from __future__ import annotations

# Note: Backends are imported lazily by CredentialProvider to avoid
# loading keyring or other optional dependencies at module import time.
