add mangal patch to help with ram

pkgs/default.nix

@@ -1,12 +1,13 @@
 { pkgs, ... }: rec {
-  kop-hub = pkgs.callPackage ./hub/default.nix { };
+  adam-site = pkgs.callPackage ./adam-site/default.nix { };
   ente-frontend = pkgs.callPackage ./ente-frontend/default.nix { };
-  kop-website =
-    pkgs.callPackage ./website/default.nix { inherit kop-hub ente-frontend; };
+  kop-fhcalendar = pkgs.callPackage ./kop-fhcalendar/default.nix { };
+  kop-fileshare = pkgs.callPackage ./kop-fileshare/default.nix { };
+  kop-hub = pkgs.callPackage ./hub/default.nix { };
   kop-monitor = pkgs.callPackage ./kop-monitor/default.nix { };
   kop-newproject = pkgs.callPackage ./kop-newproject/default.nix { };
-  kop-fileshare = pkgs.callPackage ./kop-fileshare/default.nix { };
-  kop-fhcalendar = pkgs.callPackage ./kop-fhcalendar/default.nix { };
-  adam-site = pkgs.callPackage ./adam-site/default.nix { };
+  kop-website =
+    pkgs.callPackage ./website/default.nix { inherit kop-hub ente-frontend; };
   sddm-astronaut = pkgs.callPackage ./sddm-astronaut/default.nix { };
+  mangal-patched = pkgs.callPackage ./mangal/default.nix { mangal = pkgs.mangal; };
 }

pkgs/mangal/default.nix

@@ -0,0 +1,6 @@
+{ mangal }:
+let
+  addPatches = pkg: patches:
+    pkg.overrideAttrs
+    (oldAttrs: { patches = (oldAttrs.patches or [ ]) ++ patches; });
+in addPatches mangal [ ./mangal.diff ]

pkgs/mangal/mangal.diff

@@ -11,3 +11,18 @@ index e7d0c62..7af6542 100644
  		return fmt.Sprintf(template, query)
  	},
  	MangaExtractor: &generic.Extractor{
+diff --git a/inline/inline.go b/inline/inline.go
+index 26ad0c6..dc02fda 100644
+--- a/inline/inline.go
++++ b/inline/inline.go
+@@ -131,6 +132,10 @@ func Run(options *Options) (err error) {
+ 			if err != nil {
+ 				log.Warn(err)
+ 			}
++			// free memory after downloading
++			for _, page := range chapter.Pages {
++				page.Contents = nil
++			}
+ 		} else {
+ 			err := downloader.Read(chapter, func(string) {})
+ 			if err != nil {