feat: deploy the Conductor AskUserQuestion hook (setup + upgrade migration)

The PreToolUse hook only delivers its Conductor-prose guarantee if it's
installed, but setup skips hook registration in non-interactive (conductor/CI)
setups. Two fixes so layer 3 actually deploys:

- setup: treat a Conductor workspace as an implicit opt-in for the PreToolUse
  hook on the silent fall-through (never overriding an explicit opt-out).
- migration v1.58.0.0: re-register the hook for existing Conductor installs on
  /gstack-upgrade, idempotent and respecting plan_tune_hooks=no.

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

gstack-upgrade/migrations/v1.58.0.0.sh

@@ -0,0 +1,63 @@
+#!/usr/bin/env bash
+# Migration: v1.58.0.0 — register the PreToolUse AskUserQuestion hook for
+# existing Conductor installs.
+#
+# Why a migration: v1.58 makes the PreToolUse question-preference-hook also
+# deny the flaky Conductor AskUserQuestion and redirect to a prose decision
+# brief. But setup's hook-install block skips silently in non-interactive
+# (conductor/CI) setups, and existing users who previously declined plan-tune
+# hooks would never pick up the new Conductor backstop. This re-registers the
+# hook for Conductor users so layer 3 actually deploys.
+#
+# Affected: users who run gstack inside Conductor and don't already have the
+# PreToolUse hook installed.
+#
+# Scope guard: only acts inside a Conductor session (CONDUCTOR_* present) and
+# never overrides an explicit `plan_tune_hooks` opt-out.
+#
+# Idempotent: gstack-settings-hook dedupes by (event, matcher, source), and a
+# .done touchfile gates re-runs.
+
+set -u
+
+GSTACK_HOME="${HOME}/.gstack"
+MIGRATION_DIR="${GSTACK_HOME}/.migrations"
+DONE="${MIGRATION_DIR}/v1.58.0.0.done"
+mkdir -p "${MIGRATION_DIR}" 2>/dev/null || true
+[ -f "${DONE}" ] && exit 0
+
+# Only relevant inside Conductor — the prose-default behavior is Conductor-scoped.
+if [ -z "${CONDUCTOR_WORKSPACE_PATH:-}" ] && [ -z "${CONDUCTOR_PORT:-}" ]; then
+  touch "${DONE}"
+  exit 0
+fi
+
+SCRIPT_DIR="$(cd "$(dirname "$0")/../.." && pwd)"
+SETTINGS_HOOK="${SCRIPT_DIR}/bin/gstack-settings-hook"
+PREF_HOOK="${SCRIPT_DIR}/hosts/claude/hooks/question-preference-hook"
+CONFIG_BIN="${SCRIPT_DIR}/bin/gstack-config"
+
+# Respect an explicit opt-out — don't force a hook on a user who said no.
+_PT=$("${CONFIG_BIN}" get plan_tune_hooks 2>/dev/null || echo "")
+_PT=$(printf '%s' "${_PT}" | tr '[:upper:]' '[:lower:]' | tr -d '[:space:]')
+case "${_PT}" in
+  n|no|false|skip|off|0)
+    echo "  [v1.58.0.0] plan_tune_hooks opted out — leaving Conductor on guidance-only prose." >&2
+    touch "${DONE}"
+    exit 0
+    ;;
+esac
+
+if [ -x "${SETTINGS_HOOK}" ] && [ -x "${PREF_HOOK}" ]; then
+  "${SETTINGS_HOOK}" add-event \
+    --event PreToolUse \
+    --matcher '(AskUserQuestion|mcp__.*__AskUserQuestion)' \
+    --command "${PREF_HOOK}" \
+    --source plan-tune-cathedral \
+    --timeout 5 2>/dev/null \
+    && echo "  [v1.58.0.0] Conductor AskUserQuestion prose hook registered (PreToolUse)." >&2 \
+    || echo "  [v1.58.0.0] WARN: could not register the PreToolUse hook; run ./setup --plan-tune-hooks." >&2
+fi
+
+touch "${DONE}"
+exit 0

setup

@@ -1371,6 +1371,17 @@ if [ "$NO_TEAM_MODE" -ne 1 ] \
     *)                       PT_DECISION="prompt" ;;
   esac
 
+  # Conductor host reliability: the PreToolUse preference hook also carries the
+  # Conductor-prose enforcement (deny the flaky mcp__conductor__AskUserQuestion,
+  # redirect to a prose decision brief). A Conductor workspace setup otherwise
+  # falls through to "prompt" → the non-interactive skip below, leaving Conductor
+  # users without that backstop. Treat Conductor as an implicit opt-in — but
+  # only on the silent fall-through, never overriding an explicit --no-plan-tune-hooks.
+  if [ "$PT_DECISION" = "prompt" ] && { [ -n "${CONDUCTOR_WORKSPACE_PATH:-}" ] || [ -n "${CONDUCTOR_PORT:-}" ]; }; then
+    PT_DECISION="yes"
+    _PT_CONDUCTOR_AUTO=1
+  fi
+
   _install_plan_tune_hooks() {
     "$SETTINGS_HOOK" add-event \
       --event PostToolUse \
@@ -1405,10 +1416,15 @@ if [ "$NO_TEAM_MODE" -ne 1 ] \
     log ""
     log "Plan-tune hooks already installed. Run \`$SETTINGS_HOOK list-sources\` to inspect."
   elif [ "$PT_DECISION" = "yes" ]; then
-    # Explicit opt-in (flag / env / config). Non-interactive.
+    # Explicit opt-in (flag / env / config) or Conductor implicit opt-in. Non-interactive.
     _install_plan_tune_hooks
     log ""
-    log "Plan-tune hooks installed. Run /plan-tune anytime to inspect."
+    if [ "${_PT_CONDUCTOR_AUTO:-0}" -eq 1 ]; then
+      log "AskUserQuestion reliability hooks installed (Conductor detected): decisions"
+      log "render as a prose brief instead of the flaky AskUserQuestion tool. Inspect with /plan-tune."
+    else
+      log "Plan-tune hooks installed. Run /plan-tune anytime to inspect."
+    fi
     touch "$PLAN_TUNE_INSTALL_MARKER"
   elif [ "$PT_DECISION" = "no" ]; then
     # Explicit opt-out (flag / env / config). Non-interactive.