✨ Implement `sshctl key list` command

[AndreLeclercq]

Goal

List all SSH keys in the user's ~/.ssh directory.

Command

sshctl key list

Features

• Scan ~/.ssh/ for SSH key pairs
• Detect key types (Ed25519, RSA, ECDSA) from public key
• Handle empty directory with helpful message
• Flag orphaned keys (missing .pub file)

Example Output

  $ sshctl key list
  github-personal   Ed25519    ~/.ssh/github-personal
  id_rsa            RSA-2048   ~/.ssh/id_rsa
  work-server       RSA-4096   ~/.ssh/work-server (missing .pub file)