Default to America/Phoenix and email-alert once when the session expires

Phoenix doesn't observe DST, so schedule times stay meaningful
year-round without needing a seasonal adjustment.

notify.py reuses lunch-notifier's existing Gmail-SMTP-with-app-password
pattern rather than adding a new notification channel. The alert fires
exactly once per expiry (not on every failed scheduled run while it's
down) via a dedupe flag in notify_state.json, reset the moment a fresh
session is successfully imported.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01H6TgffxTvYhqxykAbVQg2v

docker-compose.yml

@@ -15,5 +15,8 @@ services:
     environment:
       - LOGIN_PASSWORD=${LOGIN_PASSWORD}
       - SECRET_KEY=${SECRET_KEY}
-      - TZ=${TZ:-America/New_York}
+      - TZ=${TZ:-America/Phoenix}
+      - GMAIL_USER=${GMAIL_USER:-}
+      - GMAIL_APP_PASSWORD=${GMAIL_APP_PASSWORD:-}
+      - ALERT_EMAIL=${ALERT_EMAIL:-}
     restart: unless-stopped