Fix cache strategy and warn user

Author: BhasherBEL

internal/locale/translations/en_US.json

@@ -784,6 +784,7 @@
   "page.offline.message": "You are offline",
   "page.offline.refresh_page": "Try to refresh the page",
   "page.webauthn_rename.title": "Rename Passkey",
+  "page.cache.warning": "You're viewing a cached version. Refresh to see the latest one.",
   "alert.no_shared_entry": "There is no shared entry.",
   "alert.no_bookmark": "There are no starred entries.",
   "alert.no_category": "There is no category.",

internal/template/templates/common/layout.html

@@ -132,7 +132,7 @@
     {{ if .flashErrorMessage }}
         <div role="alert" class="flash-error-message alert alert-error">{{ .flashErrorMessage }}</div>
     {{ end }}
-		<div id="offline-flag" role="alert" aria-live="assertive" aria-atomic="true" class="flash-message alert alert-warning hidden">{{ t "page.offline.warning" }}</div>
+		<div role="alert" aria-live="assertive" aria-atomic="true" class="flash-message alert alert-warning offline-hidden">{{ t "page.cache.warning" }}</div>
 
     {{template "page_header" .}}
 

internal/ui/entry_unread.go

@@ -90,6 +90,7 @@ func (h *handler) showUnreadEntryPage(w http.ResponseWriter, r *http.Request) {
 	view.Set("user", user)
 	view.Set("hasSaveEntry", h.store.HasSaveEntry(user.ID))
 	view.Set("countErrorFeeds", h.store.CountUserFeedsWithErrors(user.ID))
+	view.Set("useCachedVersion", r.Header.Get("X-Cache-Hit") != "")
 
 	// Fetching the counter here avoid to be off by one.
 	view.Set("countUnread", h.store.CountUnreadEntries(user.ID))