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/lib/services/paypal.test.ts

@@ -0,0 +1,49 @@
+import { describe, expect, it, vi, beforeEach } from "vitest";
+
+vi.mock("@/env", () => ({
+	env: {
+		PAYPAL_CLIENT_ID: "test-client-id",
+		PAYPAL_SECRET: "test-secret",
+		PAYPAL_API: "https://api-m.sandbox.paypal.com",
+		PAYPAL_CURRENCY: "USD",
+		PAYPAL_CREDITS_PER_USD: 100,
+	},
+}));
+
+import { isPayPalConfigured, creditsPerUnit, PAYPAL_API, PAYPAL_CURRENCY } from "./paypal";
+
+describe("paypal", () => {
+	it("isPayPalConfigured returns true when credentials are set", () => {
+		expect(isPayPalConfigured()).toBe(true);
+	});
+
+	it("PAYPAL_API strips trailing slashes", () => {
+		expect(PAYPAL_API.endsWith("/")).toBe(false);
+		expect(PAYPAL_API).toBe("https://api-m.sandbox.paypal.com");
+	});
+
+	it("PAYPAL_CURRENCY is uppercase", () => {
+		expect(PAYPAL_CURRENCY).toBe("USD");
+	});
+
+	it("creditsPerUnit returns the configured value", () => {
+		expect(creditsPerUnit()).toBe(100);
+	});
+});
+
+describe("paypal with missing credentials", () => {
+	it("isPayPalConfigured returns false when unset", async () => {
+		vi.resetModules();
+		vi.doMock("@/env", () => ({
+			env: {
+				PAYPAL_CLIENT_ID: "",
+				PAYPAL_SECRET: "",
+				PAYPAL_API: undefined,
+				PAYPAL_CURRENCY: "USD",
+				PAYPAL_CREDITS_PER_USD: 100,
+			},
+		}));
+		const { isPayPalConfigured: check } = await import("./paypal");
+		expect(check()).toBe(false);
+	});
+});