feat: v2.7.8 — Artifacts hub, clone related repos as extra folders, quieter resume prompt

- Artifacts (/artifacts): claude.ai pages sessions publish (captured from the
  Artifact tool's hook), pinned workspace files, skills and plugins, each
  kept as a snapshot; shared ones appear in a Hub and a skill or plugin
  installs into the viewer's own account (server/lib/artifacts.js,
  /api/artifacts, docs/plans/artifacts/).
- Workspace extra folders: clone one or more related repos beside the
  workspace and add them in one step (POST /api/lanes/:id/sources/clone).
- A pane that ended by itself while tmux kept running is no longer offered
  for resume (tmux.serverStartedAt in reconcileOrphans).
- Changes panel: a folder that is not a git repo opens on Files, and its
  files open from there.
- Plus the parallel sessions' work in this tree: File Explorer button in the
  panel header, user delete, RSA SSH keys, chat/terminal and pet fixes.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

scripts/server/agenthub-provision.sh

@@ -7,11 +7,16 @@
 #   agenthub-provision create  <name>   Linux user ah-<name>, home <USERS_ROOT>/<name>
 #   agenthub-provision disable <name>   lock the account and end its processes
 #   agenthub-provision enable  <name>   unlock it
+#   agenthub-provision delete  <name>   end its processes, remove the account
+#                                       and its home <USERS_ROOT>/<name>
 #
 # Nothing but an action and a name comes from the caller; every path comes
-# from /etc/agenthub/server.conf (root's). It never deletes an account or a
-# home, never touches an account that is not an AgentHub member (one that
-# already exists outside group agenthub-members is refused), and never
+# from /etc/agenthub/server.conf (root's). It deletes only on `delete` (an
+# admin's step-up-confirmed "Delete user" on the Users page): only an AgentHub
+# member's account, and only the home at exactly <USERS_ROOT>/<name> — a real
+# directory, never a link, removed without following links or leaving its
+# filesystem. It never touches an account that is not an AgentHub member (one
+# that already exists outside group agenthub-members is refused), and never
 # grants a member sudo.
 # @author Nguyễn Ngọc Trí Vĩ <vinnt@smartgift.vn>
 set -euo pipefail
@@ -20,7 +25,7 @@ cd /  # runuser keeps the cwd: one every account may enter
 
 die() { echo "agenthub-provision: $*" >&2; exit "${2:-1}"; }
 [ "$(id -u)" = 0 ] || die "must run as root (through sudo)"
-[ $# -eq 2 ] || die "usage: agenthub-provision create|disable|enable <name>" 2
+[ $# -eq 2 ] || die "usage: agenthub-provision create|disable|enable|delete <name>" 2
 
 CONF=/etc/agenthub/server.conf
 [ -f "$CONF" ] || die "$CONF is missing — run agenthub server install-system first"
@@ -84,5 +89,30 @@ case "$ACTION" in
     usermod --unlock "$LOGIN" >/dev/null 2>&1 || true
     echo "enabled $LOGIN"
     ;;
+  delete)
+    if id "$LOGIN" >/dev/null 2>&1; then
+      is_member || die "$LOGIN is not an AgentHub member — refusing to delete it" 4
+      # Locked first, so nothing new starts while its processes are ended.
+      usermod --lock --expiredate 1 "$LOGIN"
+      for _ in 1 2 3; do
+        pkill -KILL -u "$LOGIN" 2>/dev/null || true
+        pgrep -u "$LOGIN" >/dev/null 2>&1 || break
+        sleep 1
+      done
+      userdel "$LOGIN"
+      # Its own user group, if userdel left it and nobody else is in it.
+      if getent group "$LOGIN" >/dev/null 2>&1; then groupdel "$LOGIN" 2>/dev/null || true; fi
+    fi
+    if [ -e "$HOME_DIR" ] || [ -L "$HOME_DIR" ]; then
+      # Exactly <USERS_ROOT>/<name>: a real directory sitting directly in the
+      # (root-owned) users root — never a link a member planted elsewhere.
+      [ -d "$HOME_DIR" ] && [ ! -L "$HOME_DIR" ] || die "$HOME_DIR is not a plain directory" 5
+      ROOT_REAL=$(realpath -e "$USERS_ROOT")
+      [ "$(realpath -e "$HOME_DIR")" = "$ROOT_REAL/$NAME" ] || die "$HOME_DIR resolves elsewhere" 5
+      # rm never follows a link it removes; --one-file-system stays on this disk.
+      rm -rf --one-file-system -- "$HOME_DIR"
+    fi
+    echo "deleted $LOGIN $HOME_DIR"
+    ;;
   *) die "unknown action: $ACTION" 2 ;;
 esac