refactor: resolve hotel name directly from HOTEL_NAME env

resolveHotelName() now returns env.HOTEL_NAME directly — the single source
of truth. The CMS hotel_name site setting and its DEFAULTS entry are removed
as dead code since they no longer influence the displayed name.

Call sites are unchanged (still await resolveHotelName()); only the lookup
behind it is gone, so the public site always shows the configured env name
with no DB round-trip and no preset.

vitest.config.ts

@@ -19,6 +19,7 @@ export default defineConfig({
 		// unit tests run without a populated .env.
 		env: {
 			SKIP_ENV_VALIDATION: "1",
+			HOTEL_NAME: "TestHotel",
 			DATABASE_URL: "mysql://root:root@localhost:3306/test",
 		},
 		testTimeout: 10000,