fix nextcloud auto-update crashing on nix-managed apps

common/server/nextcloud.nix

@@ -11,6 +11,9 @@ let
 
   # Hardcoded public ip of ponyo... I wish I didn't need this...
   public_ip_address = "147.135.114.130";
+
+  nixManagedApps = builtins.attrNames cfg.extraApps;
+  nixManagedAppsPattern = lib.concatStringsSep "|" nixManagedApps;
 in
 {
   config = lib.mkIf cfg.enable {
@@ -42,6 +45,28 @@ in
       # Allows installing Apps from the UI (might remove later)
       appstoreEnable = true;
     };
+
+    # Nix-managed apps (extraApps) live in the read-only nix store. If Nextcloud
+    # downloads a newer version into store-apps/, both get loaded by PHP causing
+    # a fatal class redeclaration error and leaving NC stuck in maintenance mode.
+    # Fix: (1) clean store-apps/ of nix-managed duplicates before setup/upgrade,
+    # (2) skip nix-managed apps during auto-updates.
+    systemd.services.nextcloud-setup.preStart = lib.mkAfter ''
+      for app in ${lib.escapeShellArgs nixManagedApps}; do
+        if [ -d "${cfg.home}/store-apps/$app" ]; then
+          rm -rf "${cfg.home}/store-apps/$app"
+        fi
+      done
+    '';
+    systemd.services.nextcloud-update-plugins = {
+      path = [ config.services.nextcloud.occ ];
+      serviceConfig.ExecStart = lib.mkForce (toString (pkgs.writeShellScript "nextcloud-update-non-nix-apps" ''
+        apps=$(nextcloud-occ app:update --showonly | awk '{print $1}' | grep -vE '^(${nixManagedAppsPattern})$' || true)
+        for app in $apps; do
+          nextcloud-occ app:update "$app"
+        done
+      ''));
+    };
     age.secrets.nextcloud-pw = {
       file = ../../secrets/nextcloud-pw.age;
       owner = "nextcloud";