New standalone service that receives authenticated HTTP POSTs (e.g. from a
cronjob elsewhere on the home network) and posts them to a Discord channel
via an Incoming Webhook. Fire-and-forget, no dependency on discord-bot's bot
session at all - mirrors alexa-bridge's precedent of a small bridge service
with its own HTTP listener and auth rather than adding an inbound edge to an
existing internal service.
Wires alert-bridge into go.work, CI (changes filter, test job, new
build-alert-bridge job), and the other five Dockerfiles' COPY lines.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
