refactor: full codebase overhaul — dead code removal, env validation, logger migration, date consolidation, Prisma schema cleanup, button consistency, useEffect deps, test coverage

- env.ts: added 10 missing Zod-validated env vars (imager, paypal currency, argon2/bcrypt params)
- Migrated 6 modules from process.env to validated env.* (auth, proxy-auth, paypal, password, redis, imager, moderation, alert, logger)
- Replaced console.warn/error with pino logger in 9 server-side modules
- Removed 50+ dead exports (SWF wrappers, coalesceHotelName, signIn, isStaff re-export, formatTimestamp, Skeleton/SkeletonCard, 4 unused housekeeping sections)
- Consolidated date formatting: 28 files migrated to shared formatDate() from @/lib/format-date
- Wired 4 radio/settings API routes through cached siteSettings service instead of raw Prisma queries
- Added getMany()/getAll() helpers to SiteSettings service
- Removed 88 dead Prisma model definitions (schema 2763→1846 lines)
- Created admin action-helper.ts with wrapAction() for standardized error handling
- Fixed useEffect dependency arrays in 4 data-heavy components
- Replaced raw btn CSS classes with shadcn Button component across admin pages
- Stripped dead i18n namespaces (common, pages.client) from all 22 translation files
- Removed 2 dead scripts (create-release.sh, check-local-imports.ts)
- Fixed knip.json configuration
- Added 7 new test suites: format-date, paypal, moderation, alert, webhook, action-helper, and fixed password.test.ts for env mocking
- All 358 tests passing across 72 test files
- TypeScript: 0 errors

src/app/admin/articles/page.tsx

@@ -2,8 +2,10 @@ import Link from "next/link";
 import { redirect } from "next/navigation";
 import { getTranslations } from "next-intl/server";
 import { StatusCard } from "@/components/admin/dashboard";
+import { Button } from "@/components/ui/button";
 import { ArticleCard } from "@/components/admin/article-card";
 import { canAccess, getAdminContext, PERMS } from "@/lib/permissions";
+import { formatDate } from "@/lib/format-date";
 import { prisma } from "@/lib/prisma";
 
 export const dynamic = "force-dynamic";
@@ -48,15 +50,17 @@ export default async function AdminArticles({
 	}
 
 	const latest = articles[0]?.createdAt
-		? articles[0].createdAt.toISOString().slice(0, 10)
+		? formatDate(articles[0].createdAt, "date")
 		: "—";
 
 	return (
 		<main>
 			<div className="flex justify-end mb-6">
-				<Link href="/admin/articles/new" className="btn btn-primary">
-					{t("newArticle")}
-				</Link>
+				<Button variant="default" asChild>
+					<Link href="/admin/articles/new">
+						{t("newArticle")}
+					</Link>
+				</Button>
 			</div>
 
 			{error ? (