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/import/furni/import-furni-client.tsx

@@ -262,7 +262,7 @@ export function ImportFurniClient() {
 		}
 		document.addEventListener("keydown", onKeyDown);
 		return () => document.removeEventListener("keydown", onKeyDown);
-	});
+	}, [toggleSelectAll]);
 
 	// Derived: unique categories from loaded items
 	const categories = useMemo(() => {
@@ -354,7 +354,6 @@ export function ImportFurniClient() {
 
 	// Auto-search with debounce (500ms)
 	const debounceRef = useRef<ReturnType<typeof setTimeout> | null>(null);
-	// biome-ignore lint/correctness/useExhaustiveDependencies: explicitly chosen here, see surrounding code
 	useEffect(() => {
 		if (debounceRef.current) clearTimeout(debounceRef.current);
 		debounceRef.current = setTimeout(() => {
@@ -367,7 +366,7 @@ export function ImportFurniClient() {
 		return () => {
 			if (debounceRef.current) clearTimeout(debounceRef.current);
 		};
-	}, [searchTerm]);
+	}, [searchTerm, fetchItems, activeSearch, statusFilter]);
 
 	// Re-fetch when status filter changes to/from missing-nitro
 	const prevStatusRef = useRef(statusFilter);