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/(site)/apply/staff/page.tsx

@@ -5,6 +5,7 @@ import { applyStaff } from "@/actions/applications";
 import { ContentCard, EmptyState } from "@/components/public/ui";
 import { auth } from "@/lib/auth";
 import { prisma } from "@/lib/prisma";
+import { formatDate } from "@/lib/format-date";
 import { resolveHotelName } from "@/lib/hotel-name";
 
 export const dynamic = "force-dynamic";
@@ -55,11 +56,6 @@ export default async function ApplyStaffPage({
 	const userId = Number(session.user.id);
 	const hotelName = await resolveHotelName();
 
-	function formatDeadline(d: Date | null | undefined): string {
-		if (!d) return t("noDeadline");
-		return d.toISOString().slice(0, 16).replace("T", " ");
-	}
-
 	// ── Open positions ──────────────────────────────────────────
 	// Each query is isolated so a DB hiccup degrades that section to empty
 	// rather than 500-ing the whole page.
@@ -149,7 +145,7 @@ export default async function ApplyStaffPage({
 								<div className="content-card-body">
 									<p style={{ margin: "0 0 0.5rem" }}>{position.description}</p>
 									<p className="muted" style={{ margin: "0 0 0.75rem" }}>
-										{t("deadline", { date: formatDeadline(position.applyTo) })}
+										{t("deadline", { date: formatDate(position.applyTo, "datetime", t("noDeadline")) })}
 									</p>
 
 									{alreadyApplied ? (