fix(notifications): include remote server in Docker cleanup messages

[dscamargo]

What is this PR about?

This PR updates Docker cleanup notifications for remote servers to include the server name and ID, making it clear where the cleanup was executed. The server-specific message is now used consistently
across all notification channels.

Confidence Score: 5/5

The PR appears safe to merge. No new actionable issue remains.

Summary

Docker cleanup notifications now name the server that was cleaned. Scheduled and immediate cleanups use the same server-specific message across email and other notification channels.

• Passes server names into cleanup scheduling and direct cleanup notifications.
• Shows the server name and ID in notification messages.
• Escapes the message for email, HTML, Markdown, and Slack-style formats.

_{Reviews (2) · Last reviewed commit: "fix(notifications): use escaped Markdown..."}

[narcisonunez]

The Discord message wraps the markdown-escaped markdownMessage inside a triple-backtick code block, but code blocks render literally in Discord (no markdown parsing happens inside them). This means the backslashes inserted by escapeMarkdown show up as visible characters instead of being interpreted

[narcisonunez]

The Slack attachment escapes the message with escapeSlackMrkdwn and places it in a field value, but the attachment object never sets mrkdwn_in: ["fields"] — unlike build-error.ts / build-success.ts, which do set it. Without that flag, Slack does not parse the field as markdown, so the escape backslashes inserted by escapeSlackMrkdwn render literally instead of being stripped/interpreted.

[narcisonunez]

Please, tests this and upload screenshots if possible. Make sure this renders properly