[maca134]

Alert titles and bodies included task names and IdP emails verbatim, so a user could make an alert ping a channel (<!channel>, @here, _@channel) or carry a link (<url|text>, [x](url), plain URLs) to the admins' alert channel.

What changed (apps/api/src/lib/alerts.ts):

• Whole alert title + body, service-neutral (one text goes to every shoutrrr service, so no per-service escapes showing up as < or \[):
  • < > → ‹ ›
  • zero-width space after an @ that starts a word (emails like a@b.c unchanged)
  • zero-width space in ](
  • control characters except the body's own newlines → space
• User-set text only (task name, email/sub, ended-session sub): newlines and U+2028/2029 → space so they can't add lines; :// split by a zero-width space so URLs don't autolink.
• Tests: one shared task POST helper in alerts.test.ts.

Tested: new cases in apps/api/test/alerts.test.ts for a hostile email on a terminal alert and a hostile task name + email on a task_failed alert (title and body); both fail on the old code. bun run verify passes (api 140 pass / 10 skip, web 22, root 13).

Not covered: bare domains without a scheme can still autolink in Slack; rendering wasn't checked in real Slack/Discord/Mattermost, only the text handed to shoutrrr.