Initial commit: notification-elements-demo app

Interactive Angular 19 demo for @sda/notification-elements-ui with
6 sections: Bell & Feed, Notification Center, Inbox, Comments &
Threads, Mention Input, and Full-Featured layout. Includes mock
data, dark mode toggle, and real-time event log.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

node_modules/make-fetch-happen/lib/cache/index.js

@@ -0,0 +1,49 @@
+const { NotCachedError } = require('./errors.js')
+const CacheEntry = require('./entry.js')
+const remote = require('../remote.js')
+
+// do whatever is necessary to get a Response and return it
+const cacheFetch = async (request, options) => {
+  // try to find a cached entry that satisfies this request
+  const entry = await CacheEntry.find(request, options)
+  if (!entry) {
+    // no cached result, if the cache mode is 'only-if-cached' that's a failure
+    if (options.cache === 'only-if-cached') {
+      throw new NotCachedError(request.url)
+    }
+
+    // otherwise, we make a request, store it and return it
+    const response = await remote(request, options)
+    const newEntry = new CacheEntry({ request, response, options })
+    return newEntry.store('miss')
+  }
+
+  // we have a cached response that satisfies this request, however if the cache
+  // mode is 'no-cache' then we send the revalidation request no matter what
+  if (options.cache === 'no-cache') {
+    return entry.revalidate(request, options)
+  }
+
+  // if the cached entry is not stale, or if the cache mode is 'force-cache' or
+  // 'only-if-cached' we can respond with the cached entry. set the status
+  // based on the result of needsRevalidation and respond
+  const _needsRevalidation = entry.policy.needsRevalidation(request)
+  if (options.cache === 'force-cache' ||
+      options.cache === 'only-if-cached' ||
+      !_needsRevalidation) {
+    return entry.respond(request.method, options, _needsRevalidation ? 'stale' : 'hit')
+  }
+
+  // if we got here, the cache entry is stale so revalidate it
+  return entry.revalidate(request, options)
+}
+
+cacheFetch.invalidate = async (request, options) => {
+  if (!options.cachePath) {
+    return
+  }
+
+  return CacheEntry.invalidate(request, options)
+}
+
+module.exports = cacheFetch