Code-review follow-up to PR10b-e:
- DetailHeaderStrip + KPITile: border-slate-200 → border-border so dark
mode doesn't paint a bright halo around the gradient strip.
- Topbar avatar: ring-white → ring-background so the 2px ring tracks
the surface (matches the sidebar footer pattern).
- KpiTileSkeleton stripe: bg-slate-100 → bg-muted for parity with
shadcn skeleton tokens in dark mode.
- Sidebar <aside>: add `relative` so the absolute-positioned
collapse-toggle button anchors to the sidebar itself rather than
the nearest positioned ancestor.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Replaces flat Card-based KPI rendering with KPITile (gradient-brand-soft + accent
stripe). Adds polished gradient PageHeader to DashboardShell with eyebrow, KPI
sub-line, description. Tile-shaped skeletons replace the four CardSkeletons during
KPI load.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>