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/shared/MoShiro.Protocol/Rpc/MoShiroRpc.cs

@@ -15,6 +15,7 @@ public static class MoShiroMethods
     public const string Host = "moshiro.host";
     public const string UpdateOffer = "moshiro.update.offer";
     public const string UpdateApply = "moshiro.update.apply";
+    public const string Schedule = "moshiro.schedule";
 
     // Probe ↔ Agent（点对点会话）
     public const string Clock = "moshiro.clock";
@@ -238,6 +239,17 @@ public sealed class UpdateOfferParams
     public string Signature { get; set; } = "";
 }
 
+/// <summary>
+/// 面板给节点的定时重启设置（<c>moshiro.schedule</c> 通知）：<c>restart_at</c> 形如 <c>04:30+08:00</c>，为空表示不定时重启。
+/// 节点连上时补发、设置变化时群发；节点本地写了 <c>restart_at</c> 或环境变量 <c>MOSHIRO_RESTART_AT</c> 时以本地为准。
+/// 节点只是到点自己有序退出，由服务管理器拉起，不执行任何命令。
+/// </summary>
+public sealed class ScheduleParams
+{
+    [JsonPropertyName("restart_at")]
+    public string? RestartAt { get; set; }
+}
+
 /// <summary>宿主机更新器已经验证过的可用更新。</summary>
 public sealed class UpdateAvailable
 {
@@ -560,6 +572,7 @@ public static class FragmentKeys
 [JsonSerializable(typeof(AgentEventParams))]
 [JsonSerializable(typeof(ProbeAgentList))]
 [JsonSerializable(typeof(UpdateOfferParams))]
+[JsonSerializable(typeof(ScheduleParams))]
 [JsonSerializable(typeof(UpdateStatus))]
 [JsonSerializable(typeof(ProbeHeartbeatExtra))]
 [JsonSerializable(typeof(ProbeHelloMeta))]