feat(roles): add rclone-mount role for WebDAV mounts

Add a new system-level role for mounting WebDAV filesystems via rclone.
Includes rclone-torbox-setup helper script that uses rbw to bootstrap
credentials from Bitwarden.

Key features:
- Configurable WebDAV URL, username, mount point
- VFS cache mode and buffer size tuning for media streaming
- RequiresMountsFor option for ZFS pool dependencies
- Obscured password storage via environment file

Enable on john-endesktop for TorBox WebDAV access by rdt-client and
Jellyfin. Mount waits for /media ZFS pool before starting.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

machines/john-endesktop/configuration.nix

@@ -90,6 +90,8 @@ with lib;
     htop
     tmux
     zfs
+    rclone
+    custom.rclone-torbox-setup  # Helper script to set up TorBox credentials via rbw
   ];
 
   # Enable SSH
@@ -126,6 +128,26 @@ with lib;
 
   roles.virtualisation.enable = true;
 
+  # TorBox WebDAV mount for rdt-client and Jellyfin
+  roles.rclone-mount = {
+    enable = true;
+    mounts.torbox = {
+      webdavUrl = "https://webdav.torbox.app";
+      username = "john@ogle.fyi";  # TorBox account email
+      mountPoint = "/media/media/torbox-rclone";
+      environmentFile = "/etc/rclone/torbox.env";
+      vfsCacheMode = "full";  # Best for streaming media
+      dirCacheTime = "5m";
+      extraArgs = [
+        "--buffer-size=64M"
+        "--vfs-read-chunk-size=32M"
+        "--vfs-read-chunk-size-limit=off"
+      ];
+      # Wait for ZFS media pool to be mounted before starting
+      requiresMountsFor = [ "/media" ];
+    };
+  };
+
   # Time zone
   time.timeZone = "America/Los_Angeles"; # Adjust as needed