v0.28.38 — Inline classroom playback and Fire TV controls

BackToSchool classrooms now play NixAmp streams and direct HTTPS media inline, without navigating an embedded page.

• Persistent play/pause, seek, mute, and full-screen controls.
• Fire TV directional navigation with visible focus and a compact classroom header.
• Native Fire TV media-key forwarding; Back exits full screen before leaving the classroom.
• Authenticated HLS channel playback, retry handling, and connection cleanup when leaving a class.
• Chat and event updates preserve playback, focus, and scrolling.

Pairux live sessions still require a separate direct playback integration. They show a clear explanation on TV and an external viewing link on other browsers.

Fire TV 1.0.1 (version code 2) passes Android lint and compilation, but its signed APK is not included: the signing secrets are missing. The original key is required for compatible sideload updates; an Amazon-managed-signing recovery path must be confirmed separately. The web player changes are already deployed to BackToSchool.help; native media-key changes require the new APK.

Validation: 835 tests passed, six database-dependent tests skipped; typechecks and production builds passed. Browser checks covered MP4, authenticated HLS, remote controls, full-screen Back, mobile layout, focus preservation, retries, and cleanup. Physical Fire TV testing remains outstanding.