qbt: fix categories

services/qbittorrent.nix

@@ -6,6 +6,11 @@
   inputs,
   ...
 }:
+let
+  categoriesFile = pkgs.writeText "categories.json" (
+    builtins.toJSON (lib.mapAttrs (_: path: { save_path = path; }) service_configs.torrent.categories)
+  );
+in
 {
   imports = [
     (lib.serviceMountWithZpool "qbittorrent" service_configs.zpool_hdds [
@@ -135,6 +140,22 @@
     UMask = lib.mkForce "0007";
   };
 
+  # Pre-define qBittorrent categories with explicit save paths so every
+  # torrent routes to its category directory instead of the SavePath root.
+  systemd.tmpfiles.settings.qbittorrent-categories = {
+    "${config.services.qbittorrent.profileDir}/qBittorrent/config/categories.json"."L+" = {
+      argument = "${categoriesFile}";
+      user = config.services.qbittorrent.user;
+      group = config.services.qbittorrent.group;
+      mode = "1400";
+    };
+  };
+
+  # Ensure category directories exist with correct ownership before first use.
+  systemd.tmpfiles.rules = lib.mapAttrsToList (
+    _: path: "d ${path} 0770 ${config.services.qbittorrent.user} ${service_configs.media_group} -"
+  ) service_configs.torrent.categories;
+
   services.caddy.virtualHosts."torrent.${service_configs.https.domain}".extraConfig = ''
     import ${config.age.secrets.caddy_auth.path}
     reverse_proxy ${config.vpnNamespaces.wg.namespaceAddress}:${builtins.toString config.services.qbittorrent.webuiPort}