Keep 2.21.3

Keep 2.21.3 improves first-time installation and setup.

• Setup completion stays disabled until the required Plex, Maintainerr, collection, and enabled email settings are saved. A checklist explains what is missing, and live connections are verified before setup finishes.
• Connections adds Return to Setup while initial setup is unfinished. Setup uses System or your saved appearance preference, with consistent hover and keyboard focus styling.
• Missing prerequisites show platform-specific installation commands or official setup links. The installer prints guidance without installing tools or changing Docker permissions automatically.
• The README adds the Keep logo and official prerequisite links; installation instructions explain the setup code and guided browser steps.
• SMTP authentication failures are handled cleanly when a username is configured without a saved password; unauthenticated relays remain supported.

The image supports Linux amd64 and arm64. Both native images passed application, security, installation, recovery, and source-material checks; Windows PowerShell and filesystem checks also passed. Full Windows Docker Desktop and physical-device fresh-install acceptance are separate manual checks.

Use brspoon/keep:2.21.3 to pin this release or brspoon/keep:stable to follow the current stable release. Back up configuration and data before upgrading both Keep services together. Matching source archives, notices, checksums, and original native verification evidence are attached to this release.