feat(ci): automated docker update script + nightly cron

- scripts/docker-update.sh: git pull --ff-only, host db:migrate, docker compose
  build + up -d, health-check wait, keeps host-side PM2 'next' stopped.
  Fails safe on dirty working tree (exit 1) and on health failure (exit 3).
- cron entry: daily 03:30 -> logs/docker-update.cron.log
- README: Automatic Updates section + docker commands row

scripts/docker-update.sh

@@ -0,0 +1,89 @@
+#!/usr/bin/env bash
+# ==============================================================================
+# docker-update.sh — Automatic daily update for the Dockerized EpicNext-CMS.
+#
+# Steps:
+#   1. Verify the working tree is clean (uncommitted changes abort).
+#   2. git pull (fast-forward only).
+#   3. Run CMS migrations on the HOST (the slim runtime container has no source).
+#   4. docker compose build (auto-detects pnpm/yarn/npm via lockfile).
+#   5. docker compose up -d && wait for a healthy container.
+#   6. Record everything in update.log.
+#
+# Exit codes: 0 ok, 1 update skipped, 2 build/deploy failed, 3 health failed.
+# ==============================================================================
+
+set -uo pipefail
+
+DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+cd "$DIR" || exit 2
+
+LOG_FILE="${LOG_FILE:-$DIR/logs/docker-update.log}"
+PM2_APP="${PM2_APP:-next}" # host-side CMS that must stay stopped (port 3002)
+
+log()  { echo "[$(date '+%Y-%m-%d %H:%M:%S')] $*" | tee -a "$LOG_FILE"; }
+die()  { log "ERROR: $*"; exit "${2:-2}"; }
+
+touch "$LOG_FILE"
+
+log "=== Start docker-update ==="
+
+# --- 0. Guard: uncommitted changes would break git pull / taint deploys ---
+if ! { git diff --quiet --exit-code && git diff --cached --quiet --exit-code; }; then
+  die "working tree has uncommitted changes; commit or stash first" 1
+fi
+
+# --- 1. Pull latest ---
+git pull --ff-only --quiet 2>>"$LOG_FILE"
+pull_status=$?
+if [ $pull_status -ne 0 ]; then
+  die "git pull failed (status $pull_status)" 1
+fi
+log "git pull OK: $(git rev-parse --short HEAD)"
+
+# --- 2. Host-side migrations (idempotent; only applies CMS-owned tables) ---
+if [ -f pnpm-lock.yaml ] && command -v pnpm >/dev/null 2>&1; then
+  pnpm db:migrate >>"$LOG_FILE" 2>&1 || die "db:migrate (pnpm) failed"
+elif command -v npm >/dev/null 2>&1; then
+  npm run db:migrate >>"$LOG_FILE" 2>&1 || die "db:migrate (npm) failed"
+else
+  die "no package manager found for migrations" 2
+fi
+log "db:migrate OK"
+
+# --- 3. Rebuild the image ---
+docker compose build >>"$LOG_FILE" 2>&1 || die "docker compose build failed" 2
+log "docker compose build OK"
+
+# --- 4. Recreate the container ---
+docker compose up -d >>"$LOG_FILE" 2>&1 || die "docker compose up failed" 2
+log "docker compose up OK"
+
+# --- 5. Wait for health (up to ~4 min) ---
+healthy=0
+for i in $(seq 1 16); do
+  status="$(docker inspect --format='{{.State.Health.Status}}' epicnext-cms 2>/dev/null || true)"
+  case "$status" in
+    healthy) healthy=1; break ;;
+    unhealthy) break ;;
+  esac
+  sleep 15
+done
+
+if [ "$healthy" -eq 1 ]; then
+  log "CMS healthy after update (commit $(git rev-parse --short HEAD))"
+else
+  log "WARNING: container not healthy (status='${status:-unknown}')"
+  # Leave the container running so it can be debugged; report failure exit.
+  exit 3
+fi
+
+# --- 6. Make sure the stale host-side PM2 CMS stays stopped ---
+if command -v pm2 >/dev/null 2>&1 && pm2 jlist >/dev/null 2>&1; then
+  if pm2 list 2>/dev/null | grep -q "${PM2_APP}"; then
+    pm2 stop "$PM2_APP" >/dev/null 2>&1 && log "pm2 '${PM2_APP}' kept stopped (avoids port 3002 clash)"
+  fi
+fi
+
+log "=== docker-update finished OK ==="
+exit 0