0.1.0 (beta)

First release. Requires Magento 2.4.4 or later and commercekings/module-notification 0.1.

• Provider: Slack (slack) for a new slack channel: chat.postMessage as your own app's bot, the bot token
  per website (stored encrypted, a sensitive setting); recipients are channel IDs (C…, G…, D…), anything else
  is refused before it is sent.
• Safe text: & and < escaped, so shop data cannot mention @channel or anyone, or form labelled links (bare
  URLs are still linked by Slack; mrkdwn *, _, ~, ` still formats); > stays, so > lines are quotes; text
  over 39,000 characters cut with "…".
• API URL: only https on slack.com unless allow_custom_api_base_url is set (for a test double); otherwise the
  default, with one warning in the log.
• Failures: HTTP 429, 503 with Retry-After, ratelimited and service_unavailable are Notification's
  TemporaryFailureException; Slack's refusals (invalid_auth, channel_not_found, …) a SlackException with what
  to fix; 5xx, internal_error, fatal_error, unreadable answers and timeouts after the request left count as maybe
  posted (MessageSentException, never posted twice).
• Light: nothing on storefront or checkout requests; never posts during a shopper's request; 3 s to connect,
  10 s in all; lazy client and settings.
• Send test message in the admin, with its own ACL resource.
• A Slack app manifest (chat:write, chat:write.public).
• JSON posted as UTF-8 (charset=utf-8); invalid UTF-8 in a text (a cut log line) is sent as U+FFFD, not refused.