feat: add ssh server (sshd)

programs/data/config/ssh.toml

@@ -0,0 +1,7 @@
+# SSH server policy. The host key is generated locally on first start.
+[server]
+port = 22
+
+# Per-user access defaults to false when a user is not listed. The SSH Server
+# Settings applet maintains this table.
+[allow]