Pure byte-preserving extraction: the CSS block inside SHELL_HEAD moves
verbatim into crates/aura-cli/assets/aura.css and is spliced back via
concat!(.., include_str!(..), ..). Proven against a pre-change baseline:
chart HTML (aura chart 42edebd2-0/597d719b-GER40-w0) and graph HTML
(bare aura graph) regenerate sha256-identical (bcc2cc0f.., a0e6a97f..),
each deterministic across two generations. Suite 1043/0.
First half of the style pin: the asset becomes the single source the
runtime pages embed; tokens + component library follow separately.
refs #209
Brummel
652ad34b3f