MC Presence v2.0.9

Fixes

• Schedules without a tz field now auto-migrate to the browser's timezone — v2.0.8 added the timezone-aware scheduler but the Setup tab was rendering the browser's tz as a display fallback when the saved schedule.tz was empty. That made the field look configured (e.g. "America/Edmonton") while the server was silently still evaluating the window against its own system clock (UTC in a typical Unraid container) — disconnecting bots hours before the user expected. Symptom: schedule "09:00–22:00 America/Edmonton" disconnecting at 5:05 PM local because 5:05 PM Edmonton = 11:05 PM UTC > 22:00. On socket init, any bot whose schedule.tz is empty now gets stamped with the browser-resolved tz and persisted. New sessions created via createNewSession also include the browser tz from the start. The Timezone input now shows the actual saved value (with a clear "Empty — schedule will use the server's system clock until set." note if it really is empty).