R9 Web Push in decePub: one subscription per persona, each with its own token and registration

Settings gets "Notifications on this device" (PushEditor): personas, alerts in four groups, policy, a test
notification, after a one-time notice of what the push service learns. Each persona ticked gets its own service
worker registration (push-worker.js at push/{slot}/), so its own endpoint and keys, subscribed with its own token
(IHttpService's *As); nothing PrivaPub stores ties two personas together and the worker never reads the payload's
token. PushService follows the tokens (re-subscribing after a renewal), reconciles at every session start, turns
off before sign-out and drops deleted or suspended personas. A click opens that persona's notifications; the app
badge counts the unread ones. Exchanges now ask for the push scope.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01WpVCoDeM1qUTRp4fXQdfof

Components/PublicNoticeHost.razor

@@ -1,17 +1,13 @@
 @inherits LocalizableComponentBase
 @implements IDisposable
 
-@* The one-time notice before a persona's first reaction or poll vote, and before it first joins an event
-   (PublicNoticeService), in MainLayout. *@
+@* The one-time notice before a persona's first reaction or poll vote, before it first joins an event, and before this
+   device's first Web Push subscription (PublicNoticeService), in MainLayout. data-public-notice names which. *@
 <DModal Placement="DModalPlacement.ResponsiveBottom" IsOpen="Notices.IsAsking" IsOpenChanged="Closed" CloseOnBackdrop="false" CloseText="@Localizer["Close"]"
-		data-public-notice>
-	<Heading>@(Notices.Act == PublicAct.Participation ? Localizer["Joining an event is public"] : Localizer["Reactions and votes are public"])</Heading>
+		data-public-notice="@ActName">
+	<Heading>@HeadingText</Heading>
 	<ChildContent>
-		<p class="text-sm">
-			@(Notices.Act == PublicAct.Participation
-				? Localizer["The event's server shows who takes part, {0} included. Your other personas are never named.", CascadingState.Persona?.Name ?? ""]
-				: Localizer["Anyone who can see the post can see that {0} reacted to it or voted in it. Your other personas are never named.", CascadingState.Persona?.Name ?? ""])
-		</p>
+		<p class="text-sm">@NoticeText</p>
 	</ChildContent>
 	<Actions>
 		<DButton Size="DSize.Sm" OnClick="() => Notices.Answer(false)">@Localizer["Cancel"]</DButton>
@@ -22,6 +18,27 @@
 @code {
 	[Inject] PublicNoticeService Notices { get; set; }
 
+	string ActName => Notices.Act switch
+	{
+		PublicAct.Participation => "participation",
+		PublicAct.Push => "push",
+		_ => "reaction"
+	};
+
+	string HeadingText => Notices.Act switch
+	{
+		PublicAct.Participation => Localizer["Joining an event is public"],
+		PublicAct.Push => Localizer["Notifications go through your browser's push service"],
+		_ => Localizer["Reactions and votes are public"]
+	};
+
+	string NoticeText => Notices.Act switch
+	{
+		PublicAct.Participation => Localizer["The event's server shows who takes part, {0} included. Your other personas are never named.", CascadingState.Persona?.Name ?? ""],
+		PublicAct.Push => Localizer["To reach this device while decePub is closed, PrivaPub hands each notification to the push service your browser uses (Google's, Mozilla's, Apple's…). It is encrypted for this browser alone: the push service learns when a notification arrives and how big it is, never what it says, who sent it or which persona it is for. Each persona has a subscription of its own, so PrivaPub keeps nothing that ties your personas together."],
+		_ => Localizer["Anyone who can see the post can see that {0} reacted to it or voted in it. Your other personas are never named.", CascadingState.Persona?.Name ?? ""]
+	};
+
 	protected override void OnInitialized()
 	{
 		Notices.Changed += Refresh;