Theseus serves bergamot.x from its own Sia bucket (bns/bergamot/), so a
href="/shared.css" on the page resolves to bns://bergamot.x/shared.css —
not to the silentmode.st root. The ICANN mirror hid this because /shared.css
exists at the silentmode.st root; via BNS the stylesheet 404'd and the
page rendered unstyled.
Copying the two root assets into the bucket keeps the one <link rel=
"stylesheet" href="/shared.css"> href working across all three serving
paths (ICANN, gateway, BNS).
