v10.1.0

Android

• Added storageNamespace option to AndroidOptions for full namespace isolation across storage instances (SharedPreferences, KeyStore aliases, config/key storage). Use this instead of sharedPreferencesName when running multiple FlutterSecureStorage instances with different cipher configurations.
• Deprecated sharedPreferencesName in favor of storageNamespace, which provides complete isolation rather than data-only isolation.
• Added migrateWithBackup option to AndroidOptions for crash-resistant migration. When enabled, backup copies of encrypted data are created before migration starts, allowing recovery if migration fails or the app crashes mid-migration. Works in conjunction with migrateOnAlgorithmChange.
• Made KeyCipherAlgorithm and StorageCipherAlgorithm public enums.

Fixes:

• Fixed crash on biometric failure (not error).
• Fixed null safety issue in MethodRunner that could cause a crash on Android.
• Fixed config being overwritten on initialization.
• Fixed default Android key cipher not aligning with the Flutter default.

iOS / macOS

• Added useSecureEnclave option to IOSOptions and MacOsOptions to store keys in the device's Secure Enclave for hardware-backed security.

Fixes:

• Fixed kSecAttrSynchronizable being silently dropped when no access control flags are set.
• Fixed readAll not returning Secure Enclave items correctly.