Brief 6 of unify-glass-panel-surfaces convoy. Replaces the handrolled
inline `var(--glass-surface-mid)` + `backdropFilter` + malformed
`boxShadow: 'inset 0 1px 0 var(--rim-light-inner)'` on the landing
<nav> with the canonical .page-header-glass class, which already
exists in styles/globals.css for exactly this "full-bleed top band"
use case.
The malformed boxShadow was a real bug: --rim-light-inner is already
a complete `inset 0 1px 0 <color>` declaration, so wrapping it in
another `inset 0 1px 0 ...` produced invalid CSS the browser silently
dropped. Documented in styles/globals.css L748-761. The class's own
`box-shadow: var(--rim-light-inner), 0 1px 0 var(--border)` does the
right thing.
Acceptance criteria from
.convoys/unify-glass-panel-surfaces/brief-6-landing-nav-bar.md:
- [x] <nav> uses className="page-header-glass border-b"
- [x] Inline style retains only borderColor: 'var(--border)'
- [x] Heading + Sign In / Get Started buttons inside the nav unchanged
- [x] npm run lint passes (1 pre-existing warning unrelated to this PR)
Co-authored-by: Cursor <cursoragent@cursor.com>
