feat: daily node restart controlled from the admin, connect timings as a default line task [CI]

Agents and Probes exit in order at a configured time (default 04:30 UTC+8, switch and time zone in the admin settings) and the service manager starts them again; a local restart_at or MOSHIRO_RESTART_AT wins. The connect kind (TCP connect and TLS handshake timings) is now a default continuous line template, with a section on the line page.

backend/src/MoShiro.Backend.Gateway/FleetGateway.cs

@@ -67,6 +67,9 @@ public sealed class FleetGateway : IAgentGateway
     public async ValueTask NotifyUpdateOfferAsync(NodeId node, string manifest, string signature, CancellationToken ct) =>
         await Connections.NotifyAsync(node, MoShiroMethods.UpdateOffer, new UpdateOfferParams { Manifest = manifest, Signature = signature }, MoShiroJsonContext.Default.UpdateOfferParams, ct);
 
+    public async ValueTask NotifyScheduleAsync(NodeId node, string? restartAt, CancellationToken ct) =>
+        await Connections.NotifyAsync(node, MoShiroMethods.Schedule, new ScheduleParams { RestartAt = restartAt }, MoShiroJsonContext.Default.ScheduleParams, ct);
+
     public async ValueTask<bool> NotifyUpdateApplyAsync(NodeId node, CancellationToken ct) =>
         await Connections.NotifyAsync(node, MoShiroMethods.UpdateApply, new UpdateOfferParams(), MoShiroJsonContext.Default.UpdateOfferParams, ct);
 }