Send backup alerts to a person, not just the shared inbox

Failures went to REPORT_EMAIL, which is the media@ shared inbox the Sunday digest
already uses. An alert competing with a routine weekly mail in a shared inbox is
an alert that gets scrolled past, which is most of the way back to the logfile
nobody read.

ALERT_EMAIL is now a separate, comma-separated list for breakage only, falling
back to REPORT_EMAIL so a machine whose .env predates this still alerts somewhere
rather than silently not at all.

Verified by sending one test alert, which arrived.

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

server/.env.example

@@ -18,6 +18,12 @@ ADMIN_PASSWORD=changeme
 # blank to send only the per-team emails.
 REPORT_EMAIL=you@example.com
 
+# Where BREAKAGE is reported, comma separated. Kept separate from REPORT_EMAIL so a
+# failure alert does not have to compete with the weekly digest for attention, and so
+# it can reach a person rather than only a shared inbox. Falls back to REPORT_EMAIL.
+# Used by scripts/alert.js, which backup-to-drive.sh calls on every failure path.
+ALERT_EMAIL=you@example.com,team@example.com
+
 # Cron schedule for the digest. Default: every Sunday at 3:00 PM.
 # Format: minute hour day-of-month month day-of-week
 REPORT_CRON=0 15 * * 0