Refactor: implemented Repository Factory and Async Mutator Engine. Decoupled storage logic and enforced Dependency Injection across CLI and Web API. Updated documentation.

tests/test_smtp_relay.py

@@ -7,7 +7,7 @@ from decnet.services.smtp_relay import SMTPRelayService
 def test_smtp_relay_compose_fragment():
     svc = SMTPRelayService()
     fragment = svc.compose_fragment("test-decky", log_target="log-server")
-    
+
     assert fragment["container_name"] == "test-decky-smtp_relay"
     assert fragment["environment"]["SMTP_OPEN_RELAY"] == "1"
     assert fragment["environment"]["LOG_TARGET"] == "log-server"
@@ -15,7 +15,7 @@ def test_smtp_relay_compose_fragment():
 def test_smtp_relay_custom_cfg():
     svc = SMTPRelayService()
     fragment = svc.compose_fragment(
-        "test-decky", 
+        "test-decky",
         service_cfg={"banner": "Welcome", "mta": "Postfix"}
     )
     assert fragment["environment"]["SMTP_BANNER"] == "Welcome"