sendgrid automations

[th0rgall]

• feat: sync host status to SendGrid
• refactor: pure real-time user data loading (fixes #299)
• fix: don't reset auth state needlessly during auth
• refactor: user data & auth cleanup
• refactor: standardise import aliases to $ (remove old @)
• docs: explain dev server kill procedure
• fix: unsubscribe from chat message observer on logout.
• fix: prevent crash when Discourse is not enabled on staging
• fix: remove eslint consistent-return warning
• feat: link translated verification emails

[github-actions[bot]]

Visit the preview URL for this PR (updated for commit 5cf4b7e):

https://wtmg-dev--pr307-sendgrid-automations-medxb2w0.web.app

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