TautWeekly for Plex v0.9.3

v0.9.3 corrects the newsletter's color-scheme opt-in for Apple Mail while
retaining one dark-first design and no recipient-facing theme selector.

Diagnosis and correction

v0.8.4 added explicit dark backgrounds and the standards-valid
color-scheme: dark only value. A follow-up report showed that an iPhone mail
client could still render the delivered newsletter with a light palette.

Apple's email-specific guidance documents color-scheme: light dark for rich
HTML messages that provide their own dark-mode styling. v0.9.3 now advertises
that compatible pair through both color-scheme meta elements and the root CSS
declaration. The normal styles remain dark, and the existing
prefers-color-scheme: dark block reasserts the same dark canvas and cards, so
both declared modes retain TautWeekly's existing appearance.

The change applies to newsletter and welcome emails on Windows, NAS/Docker,
and macOS. PreviewAll tests inspect every generated state, while SendTest
captures and decodes the MIME HTML part to verify the exact declarations that
reach SMTP. Packaged-renderer tests also reject the previous dark-only value.

Client limitations

Mail clients remain free to ignore supported CSS or apply their own theme and
accessibility transformations. In particular, Gmail does not document support
for color-scheme or prefers-color-scheme in email. Explicit inline colors,
table bgcolor attributes, and readable text contrast therefore remain in
place as the safest fallback, but no HTML email can force identical rendering
in every client.

References:

• Apple: Supporting Dark Mode in Your Web Content
• WebKit: Dark Mode Support in WebKit
• Gmail: CSS Support

Privacy and boundaries

This change affects only static HTML metadata and CSS. It does not access or
store credentials, recipient data, production archives, or generated
newsletters.

Platform baselines

• Windows Portable 1.8.0
• NAS/Docker Portable 1.2.0
• macOS Portable 1.1.0
• Native Linux 1.1.0
• FreeBSD/Podman 1.1.0