Add tofa docs

[gylli251]

Adds the companion documentation for the tofa Sandbox role in saltyorg/Sandbox#556.

• Adds the tofa app page with deployment, first-run claim, hardware transcoding, and remote access guidance.
• Adds tofa to the media-server index and Sandbox navigation.
• Documents the setup token needed to claim the server through a public domain, the standard media and transcode paths, and hardware acceleration behavior.

The guidance was checked against the role defaults in the Sandbox PR and against the server's own setup gate.