refactor: consolidate card components into a single SurfaceCard

Replace the three near-identical public card primitives (ContentCard for
content pages, SectionCard for auth/account, and the new SurfaceCard) by
merging SectionCard into SurfaceCard, which now supports an optional header
(title/icon/action). Every remaining ad-hoc inline `rounded-2xl border`
card across (site) is converted to SurfaceCard, preserving each card's unique
visuals (background images, blur, gradients) via the style passthrough.

Net result: the public site uses exactly two card components — ContentCard
(CMS/content pages) and SurfaceCard (everything else) — and the shadcn Card
in components/ui/card.tsx is left untouched for admin.

Also deletes the now-unused components/home-section.tsx.

src/app/(site)/me/page.tsx

@@ -254,8 +254,8 @@ export default async function MePage({
 				) : null}
 
 				<Reveal>
-					<div
-						className="relative overflow-hidden rounded-2xl border p-6 flex items-start gap-6"
+					<SurfaceCard
+						className="relative p-6 flex items-start gap-6"
 						style={{
 							background: `linear-gradient(135deg, color-mix(in srgb, var(--color-primary) 12%, var(--color-surface)), var(--color-surface))`,
 							borderColor:
@@ -343,13 +343,13 @@ export default async function MePage({
 								</span>
 							</div>
 						</div>
-					</div>
+					</SurfaceCard>
 				</Reveal>
 
 				{alertRaw ? (
 					<Reveal delay={0.05}>
-						<div
-							className="rounded-2xl border px-6 py-4 text-center"
+						<SurfaceCard
+							className="px-6 py-4 text-center"
 							style={{
 								background:
 									"color-mix(in srgb, var(--color-accent) 12%, transparent)",
@@ -363,7 +363,7 @@ export default async function MePage({
 							>
 								{alertRaw}
 							</p>
-						</div>
+						</SurfaceCard>
 					</Reveal>
 				) : null}