[asap] Audio files missing response headers required by Chrome when requested from public

[colepeters]

Describe the issue
Audio files (in this case, audio/mpeg) served from the Enhance public directory are missing some response headers that are required by Chrome for interacting with HTMLMediaElement APIs.

However, when served from static/, the correct headers are in place.

The missing headers are:

• Accept-Ranges: bytes
• Content-Range: bytes <bytes>/<total-bytes>

Steps to reproduce
Steps to reproduce the behavior:

1. Go to https://dance-7id.begin.app/player/foo
2. Inspect the response headers for arttr.mp3
3. Seeking through the track via the range input does not work

Expected behavior
The missing headers should be included in the response.

Desktop
Please complete the following information (if appropriate):

• OS: macOS
• Browser Chrome
• Version 116