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/radio/embed/embed-snippet.tsx

@@ -1,6 +1,7 @@
 "use client";
 
 import { useState } from "react";
+import { Button } from "@/components/ui/button";
 
 /**
  * Read-only copy box for an embed snippet. Renders the code inside a
@@ -42,9 +43,9 @@ export function EmbedSnippet({
 				<h2 className="m-0 text-base font-bold text-[var(--admin-text)]">
 					{title}
 				</h2>
-				<button type="button" className="btn btn-primary" onClick={copy}>
+				<Button type="button" variant="default" onClick={copy}>
 					{copied ? "Copied!" : "Copy"}
-				</button>
+				</Button>
 			</div>
 			{description ? (
 				<p className="text-xs theme-text-muted dark:theme-text-muted mb-3">

src/app/admin/radio/embed/page.tsx

@@ -1,6 +1,7 @@
 import Link from "next/link";
 import { getTranslations } from "next-intl/server";
 import { StatusCard } from "@/components/admin/dashboard";
+import { Button } from "@/components/ui/button";
 import { resolveHotelName } from "@/lib/hotel-name";
 import { siteSettings } from "@/lib/services/site-settings";
 import { EmbedSnippet } from "./embed-snippet";
@@ -73,9 +74,11 @@ export default async function AdminRadioEmbedPage() {
 						{t("embedPage.noStreamUrlText")}
 					</p>
 					<p>
-						<Link href="/admin/radio/settings" className="btn btn-primary">
-							{t("embedPage.goToSettings")}
-						</Link>
+						<Button variant="default" asChild>
+							<Link href="/admin/radio/settings">
+								{t("embedPage.goToSettings")}
+							</Link>
+						</Button>
 					</p>
 				</section>
 			) : (