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/vouchers/vouchers-client.tsx

@@ -3,9 +3,11 @@
 import { useTranslations } from "next-intl";
 import { useState } from "react";
 import { createVoucher, deleteVoucher } from "@/actions/admin-vouchers";
+import { Button } from "@/components/ui/button";
 import { ConfirmDialog } from "@/components/admin/confirm-dialog";
 import { StatusCard } from "@/components/admin/dashboard";
 import { CurrencyIcon } from "@/components/shared/currency-icon";
+import { formatDate } from "@/lib/format-date";
 import { useServerAction } from "@/hooks/use-server-action";
 
 export type VoucherRow = {
@@ -19,11 +21,6 @@ export type VoucherRow = {
 	status: "active" | "expired" | "usedUp";
 };
 
-function fmtDate(iso: string | null): string {
-	if (!iso) return "—";
-	return iso.slice(0, 16).replace("T", " ");
-}
-
 export function VouchersClient({
 	vouchers,
 	canEdit,
@@ -155,13 +152,13 @@ export function VouchersClient({
 							/>
 						</label>
 					</div>
-					<button
+					<Button
 						type="submit"
-						className="btn btn-primary"
+						variant="default"
 						disabled={isPending}
 					>
 						{isPending ? t("form.saving") : t("form.create")}
-					</button>
+					</Button>
 				</form>
 			)}
 
@@ -216,21 +213,21 @@ export function VouchersClient({
 											)}
 										</td>
 										<td className="text-sm theme-text-muted dark:theme-text-muted whitespace-nowrap">
-											{fmtDate(v.expiresAt)}
+											{formatDate(v.expiresAt ? new Date(v.expiresAt) : null)}
 										</td>
 										<td className="text-sm theme-text-muted dark:theme-text-muted whitespace-nowrap">
-											{fmtDate(v.createdAt)}
+											{formatDate(v.createdAt ? new Date(v.createdAt) : null)}
 										</td>
 										{canEdit && (
 											<td>
-												<button
+												<Button
 													type="button"
-													className="btn btn-danger"
+													variant="destructive"
 													disabled={isPending}
 													onClick={() => setPendingDelete(v)}
 												>
 													{t("delete")}
-												</button>
+												</Button>
 											</td>
 										)}
 									</tr>