Fix v0.6.13 spacing regressions with half-step tokens (--sp-1h 6px,
--sp-2h 10px). Purge ~65 stale hex/rgba fallback values from var() calls
including all old gold #b38a4e references. Self-host DM Sans and JetBrains
Mono woff2 fonts, eliminating Google Fonts CDN dependency. Standardize
border-radius to three tokens (--radius-sm 4px, --radius 8px, --radius-lg
12px) across all kernel CSS and 12 extension packages.
Also fixes: theme settings showing resolved mode instead of stored preference,
surface-inner overflow causing notes scrollbar and chat input clipping at
high zoom, user menu drift at scale >100% from zoom-unaware fixed positioning,
and three undefined CSS variable references.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
