Bust cached stylesheet on deploy

public/sw.js

@@ -1,4 +1,4 @@
-const CACHE_NAME = "roast-planner-static-v6";
+const CACHE_NAME = "roast-planner-static-v7";
 // Only /app is precached as a navigable page: it is a data-free authenticated shell (draft
 // data lives only in account-scoped local storage, and logout clears that namespace), so it is
 // the one page that is both safe and useful to relaunch offline. The marketing page, auth
@@ -7,7 +7,7 @@ const CACHE_NAME = "roast-planner-static-v6";
 // stale content.
 const APP_SHELL = [
 	"/app",
-	"/app.css",
+	"/app.css?v=20260730-5ef8274",
 	"/worksheet.css",
 	"/manifest.webmanifest",
 	"/icon.svg",