Add device agent library

Provide enrollment, elevated install, posture checks, keystore, and
system-tray helpers shared by the probo-agent binary.

Signed-off-by: Ludovic Vielle <ludovic@probo.com>

pkg/deviceagent/config_paths_other.go

@@ -27,3 +27,9 @@ package deviceagent
 func DefaultConfigDir() string {
 	return "/var/lib/probo-agent"
 }
+
+// DefaultEnrollmentRunDir returns the runtime directory for the public
+// enrollment marker on non-Windows hosts.
+func DefaultEnrollmentRunDir() string {
+	return "/var/run/probo-agent"
+}