feat(decman): manage npm packages and deploy sddm theme assets

system-config/modules/packages.py

@@ -7,6 +7,8 @@ from pathlib import Path
 import decman
 from decman.plugins import aur, pacman
 
+from modules import npm_packages
+
 ROOT = Path(__file__).resolve().parents[1]
 PACKAGES = ROOT / "packages"
 
@@ -34,6 +36,11 @@ class PackageConcern(decman.Module):
     def aur_packages(self) -> set[str]:
         return _names(PACKAGES / f"{self.concern}-aur.txt")
 
+    @npm_packages.packages
+    def global_npm_packages(self) -> set[str]:
+        path = PACKAGES / f"{self.concern}-npm.txt"
+        return _names(path) if path.exists() else set()
+
 
 def configure_no_removal_guard() -> None:
     """Keep Decman from pruning current dependency-orphans during adoption."""