feat(desktop): consolidate declarative workstation profile

Capture desktop-specific system, session, Noctalia, and Pi integration alongside shared laptop support. Retire obsolete X11 configuration and make package ownership explicit for repeatable Decman deployments.

system-config/hosts.py

@@ -5,6 +5,7 @@ from modules.packages import PackageConcern
 
 COMMON = (
     "common/core",
+    "common/hardware",
     "common/wayland",
     "common/fonts",
     "common/development",
@@ -15,7 +16,7 @@ COMMON = (
     "common/services",
 )
 LAPTOP = ("laptop/hardware",)
-DESKTOP = ()
+DESKTOP = ("desktop/local",)
 
 
 def _concerns(names: tuple[str, ...]) -> list[PackageConcern]:
@@ -28,5 +29,5 @@ def laptop() -> list:
 
 
 def desktop() -> list:
-    """Future desktop: shared concerns plus desktop-only concerns when declared."""
+    """Desktop: shared packages plus desktop-specific system configuration."""
     return [*_concerns((*COMMON, *DESKTOP)), *desktop_system()]