fix(dbus): Update systemd interface and path handling

Revised DBus interactions to explicitly use `org.freedesktop.systemd1`
interface and path. This ensures that the correct interfaces are used
and bypasses ".systemd1" magic from the library `pydbus`.

data/dbus-policy/com.revolutionpi.middleware1.conf

@@ -1,4 +1,4 @@
-<!-- /etc/dbus-1/system.d/revpi-middleware.conf -->
+<!-- /usr/share/dbus-1/system.d/com.revolutionpi.middleware1.conf -->
 <busconfig>
     <!-- Allow full access to root as the bus owner -->
     <policy user="root">
@@ -12,7 +12,7 @@
         <allow send_destination="com.revolutionpi.middleware1"
                send_interface="org.freedesktop.DBus.Introspectable"/>
         <allow send_destination="com.revolutionpi.middleware1"
-               send_interface="com.revolutionpi.middleware1.picontrol"/>
+               send_interface="com.revolutionpi.middleware1.PiControl"/>
     </policy>
 
     <!-- Standard-Policy -->

src/revpi_middleware/dbus_middleware1/system_config/revpi_config.py

@@ -324,7 +324,11 @@ def configure_gui(action: ConfigActions):
         return gui_available
 
     bus = SystemBus()
-    systemd_manager = bus.get(".systemd1")
+    systemd = bus.get(
+        "org.freedesktop.systemd1",
+        "/org/freedesktop/systemd1",
+    )
+    systemd_manager = systemd["org.freedesktop.systemd1.Manager"]
 
     if action is ConfigActions.ENABLE:
         systemd_manager.SetDefaultTarget("graphical.target", True)
@@ -384,7 +388,11 @@ def get_rfkill_index(device_class_path: str) -> Optional[int]:
 
 def simple_systemd(action: ConfigActions, unit: str):
     bus = SystemBus()
-    systemd_manager = bus.get(".systemd1")
+    systemd = bus.get(
+        "org.freedesktop.systemd1",
+        "/org/freedesktop/systemd1",
+    )
+    systemd_manager = systemd["org.freedesktop.systemd1.Manager"]
 
     if action is ConfigActions.ENABLE:
         systemd_manager.UnmaskUnitFiles([unit], False)
@@ -398,7 +406,7 @@ def simple_systemd(action: ConfigActions, unit: str):
     elif action is ConfigActions.STATUS:
         try:
             unit_path = systemd_manager.LoadUnit(unit)
-            properties = bus.get(".systemd1", unit_path)
+            properties = bus.get("org.freedesktop.systemd1", unit_path)
         except Exception:
             log.warning(f"could not get systemd unit {unit}")
             return False
@@ -408,7 +416,7 @@ def simple_systemd(action: ConfigActions, unit: str):
     elif action is ConfigActions.AVAILABLE:
         try:
             unit_path = systemd_manager.LoadUnit(unit)
-            properties = bus.get(".systemd1", unit_path)
+            properties = bus.get("org.freedesktop.systemd1", unit_path)
         except Exception:
             log.warning(f"could not get systemd unit {unit}")
             return False