perf(pwa): reduce precache asset fanout

Limit PWA precache to app shell assets and add bounded runtime caching for scoped deployments.

src/sw.ts

@@ -2,26 +2,51 @@
 /* eslint-disable no-restricted-globals */
 
 import { clientsClaim } from 'workbox-core';
+import { ExpirationPlugin } from 'workbox-expiration';
 import { precacheAndRoute, cleanupOutdatedCaches } from 'workbox-precaching';
 import { registerRoute } from 'workbox-routing';
-import { NetworkFirst } from 'workbox-strategies';
+import { NetworkFirst, StaleWhileRevalidate } from 'workbox-strategies';
 
 declare const self: ServiceWorkerGlobalScope;
 
 const precacheEntries = self.__WB_MANIFEST.filter((entry) => (typeof entry === 'string' ? entry !== 'index.html' : entry.url !== 'index.html'));
+const runtimeAssetDestinations = new Set<RequestDestination>(['font', 'image', 'manifest', 'script', 'style']);
+const scopeRoot = self.registration.scope.endsWith('/') ? self.registration.scope : `${self.registration.scope}/`;
+const scopePath = (path: string) => new URL(path, scopeRoot).pathname;
+const apiPath = scopePath('api');
+const apiPathPrefix = scopePath('api/');
+const internalPathPrefix = scopePath('_(');
+const runtimeAssetPathPrefixes = ['assets/', 'translations/'].map(scopePath);
+const isApiPath = (pathname: string) => pathname === apiPath || pathname.startsWith(apiPathPrefix);
 
 // Precache revisioned assets, but let navigations fetch fresh HTML first.
 cleanupOutdatedCaches();
 precacheAndRoute(precacheEntries);
 
 registerRoute(
-  ({ request, url }) => request.mode === 'navigate' && !url.pathname.startsWith('/api') && !/^\/_\(.*\)/.test(url.pathname),
+  ({ request, url }) => request.mode === 'navigate' && !isApiPath(url.pathname) && !url.pathname.startsWith(internalPathPrefix),
   new NetworkFirst({
     cacheName: 'html-cache',
     networkTimeoutSeconds: 3,
   }),
 );
 
+registerRoute(
+  ({ request, url }) =>
+    url.origin === self.location.origin &&
+    (runtimeAssetDestinations.has(request.destination) || runtimeAssetPathPrefixes.some((prefix) => url.pathname.startsWith(prefix))),
+  new StaleWhileRevalidate({
+    cacheName: 'runtime-static-assets',
+    plugins: [
+      new ExpirationPlugin({
+        maxEntries: 200,
+        maxAgeSeconds: 60 * 60 * 24 * 30,
+        purgeOnQuotaError: true,
+      }),
+    ],
+  }),
+);
+
 // Standard SW lifecycle methods
 self.skipWaiting();
 clientsClaim();