Edunesia API · port 9304
  GET  /api/health             — status & konfigurasi terpasang
  POST /api/meetings/ensure    — bikin Google Meet utk sesi (dipanggil app saat booking pertama)
  GET  /api/cron/reminder      — trigger manual reminder WA (H-1 & hari-H) [?key=CRON_SECRET]
  POST /api/automation/tick    — trigger manual 1 tick automation [?key=CRON_SECRET]

automation internal (jalan otomatis pas server start) — WA ke ORTU + TUTOR:
  00:05 WIB        ensure-slots (generate s/d akhir bulan depan + tutup sesi lewat)
  16/18/20:00 WIB  reminder H-1  → kelas BESOK di band yang sama
  11/13/15:00 WIB  reminder hari-H → 5 jam sebelum kelas (16/18/20)
  /30 mnt          close-past-sessions
  kill-switch: edunesia_settings key 'automation' {"enabled": false}