Modularize style.scss into _sass/v1/; refine v2…

Details

Address review feedback on the SCSS modularization:
- Split assets/css/style.scss (391 lines) into focused partials under
  _sass/v1/ (profile, news, base, beta-pill, toggles, mobile-nav,
  db-loading) behind a new _sass/v1.scss manifest. The entry now reads
  just `@import "jekyll-theme-minimal"; @import "v1";`. Partials are
  contiguous source-order slices, so their concatenation is
  byte-identical to the original inline rules.
- Merge the v2 _hero-scroll partial back into _hero so all hero rules
  are contiguous (it only existed because the db-loading block sat
  between two hero chunks in source order). This relocates the
  hero-scroll rules ahead of the disjoint db-loading rules; the line
  multiset is unchanged and the two groups share no selectors, so
  computed styles are identical.
- Rename v2 _grids partial to _records for clearer intent.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_018Z78wTEczDqpD4nqJWKRME

Files changed (13)