fix: Start SSH agent and add key silently if not already running

dotfiles/.zshrc

@@ -171,6 +171,7 @@ if command -v fabric &> /dev/null; then
 fi
 
 if [ -z "$SSH_AUTH_SOCK" ]; then
-    eval "$(ssh-agent -s)"
-    ssh-add ~/.ssh/id_rsa
-fi
+    # Start the SSH agent if not already running
+    # Add the SSH key to the agent
+    eval "$(ssh-agent -s)" >/dev/null 2>&1 && ssh-add ~/.ssh/id_ed25519 >/dev/null 2>&1
+fi