Title: Encrypt and Decrypt Text Using Provided GPG Key

As a user of the security manager,

I want to be able to encrypt and decrypt text using a GPG key that I provide,

So that I can securely exchange information with others and maintain the confidentiality and integrity of my data.

Acceptance Criteria:

GPG Key Import:

I can import my GPG key (both public and private keys) into the security manager.
The security manager should validate the format of the GPG key and confirm its successful import.
Encryption:

In the security manager interface, there should be an option to encrypt text.
Once I input the text to be encrypted and select my imported GPG public key, the security manager should provide the encrypted output.
The encrypted text should be easily copied or shared.
Decryption:

In the security manager interface, there should be an option to decrypt text.
Once I input the encrypted text and select my imported GPG private key (with necessary passphrase if required), the security manager should provide the decrypted output.
Incorrect encrypted text or mismatched GPG key should display a clear error message.
Key Management:

The security manager should provide an interface to manage (view, delete, update) the GPG keys that I have imported.
For added security, the private key's passphrase should never be stored persistently. I should be prompted for it each time I need to decrypt something.
Security:

The security manager should securely store my imported GPG keys, ensuring that they are encrypted at rest.
The process of encryption and decryption should occur locally on my device, ensuring no sensitive data is transmitted over the internet during this process.
Documentation:

The security manager should provide clear instructions and documentation on how to use the GPG encryption and decryption feature.