feat(install-options): add npm CLI reinstall helpers (Bash)

global_npm_package, cli_npm_package, read_cli_reinstall_option, and
invoke_cli_reinstall are the Bash equivalent of the PowerShell npm
reinstall helpers. Not wired into install.sh yet.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

scripts/lib/install-options.sh

@@ -36,6 +36,49 @@ read_install_options() {
   semantic_retrieval=$(read_install_boolean 'Enable Qwen3 embedding and reranking semantic retrieval?' "$semantic_retrieval") || return
 }
 
+global_npm_package() {
+  command -v npm >/dev/null 2>&1 || return 1
+  npm list -g "$1" --depth=0 --json >/dev/null 2>&1
+}
+
+cli_npm_package() {
+  case "$1" in
+    codex) printf '@openai/codex\n' ;;
+    claude) printf '@anthropic-ai/claude-code\n' ;;
+  esac
+}
+
+# read_cli_reinstall_option <client> <dry_run> -- asked once per install run, never persisted;
+# a dry run never prompts and never previews it.
+read_cli_reinstall_option() {
+  local client=$1 dry_run=$2
+  if [ "$dry_run" = true ]; then printf 'false\n'; return; fi
+  read_install_boolean "Uninstall $client and reinstall via npm?" false
+}
+
+invoke_cli_reinstall() {
+  local client=$1 dry_run=$2 summary=${3:-false}
+  local selected_client clients=() package
+  case "$client" in codex|both) clients+=(codex) ;; esac
+  case "$client" in claude|both) clients+=(claude) ;; esac
+  for selected_client in "${clients[@]}"; do
+    if [ "$selected_client" = codex ] && [ "$dry_run" = false ] && codex_process_active; then
+      printf 'WARN Codex CLI reinstall skipped because codex.exe is running. Close all Codex sessions and run install again to reinstall the CLI.\n' >&2
+      continue
+    fi
+    package=$(cli_npm_package "$selected_client")
+    if global_npm_package "$package"; then
+      CLAUDE_CODE_PACKAGE_MANAGER_AUTO_UPDATE=1 run_plugin_command "$dry_run" npm uninstall -g "$package" </dev/null || return
+    else
+      printf 'WARN %s CLI was not found as a global npm package; a non-npm installation cannot be removed automatically. Installing %s via npm alongside it.\n' "$selected_client" "$package" >&2
+    fi
+    CLAUDE_CODE_PACKAGE_MANAGER_AUTO_UPDATE=1 run_plugin_command "$dry_run" npm install -g "${package}@latest" </dev/null || return
+    if [ "$summary" = true ]; then
+      if [ "$dry_run" = true ]; then printf 'CLI %s reinstall: dry-run\n' "$selected_client"; else printf 'CLI %s reinstall: PASS\n' "$selected_client"; fi
+    fi
+  done
+}
+
 is_windows_host() {
   case "${OSTYPE:-}" in msys*|cygwin*|win32*) return 0 ;; *) return 1 ;; esac
 }