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.Application/Tasks/TaskService.cs

@@ -40,23 +40,35 @@ public sealed class TaskService
 
     public ValueTask<TaskRecord?> GetAsync(TaskId id, CancellationToken ct) => _tasks.GetAsync(id, ct);
 
-    /// <summary>首次启动时创建默认的线路任务模板（udp_echo、tcp_echo 持续运行），这样新 Agent 注册后自动获得任务。</summary>
+    /// <summary>
+    /// 创建默认的线路任务模板，这样新 Agent 注册后自动获得任务：udp_echo、tcp_echo 持续运行，connect（TCP 建连和 TLS 握手耗时，
+    /// 每分钟 6 次）也持续运行。每一批默认任务只种一次，用设置里的标记记住；你删掉的默认模板不会被重新建出来，
+    /// 后来新增的默认任务（connect）在已有部署升级后会补建一次。
+    /// </summary>
     public async ValueTask SeedDefaultsAsync(CancellationToken ct)
     {
-        if (await _settings.GetAsync("tasks.seeded", ct) is not null)
+        if (await _settings.GetAsync("tasks.seeded", ct) is null)
         {
-            return;
+            await SeedAsync([Kinds.UdpEcho, Kinds.TcpEcho], ct);
+            await _settings.SetAsync("tasks.seeded", "1", ct);
         }
 
+        if (await _settings.GetAsync("tasks.seeded.connect", ct) is null)
+        {
+            await SeedAsync([Kinds.Connect], ct);
+            await _settings.SetAsync("tasks.seeded.connect", "1", ct);
+        }
+    }
+
+    private async ValueTask SeedAsync(KindSpec[] kinds, CancellationToken ct)
+    {
         long now = _time.GetUtcNow().ToUnixTimeMilliseconds();
-        foreach (KindSpec kind in new[] { Kinds.UdpEcho, Kinds.TcpEcho })
+        foreach (KindSpec kind in kinds)
         {
             await _tasks.CreateAsync(
                 new TaskRecord(new TaskId(Ulid.NewPrefixed(TaskId.Prefix, _time)), EffectiveTasks.LineScope, null, null, kind.Id, null, new Dictionary<string, JsonElement>(), TaskSchedule.Continuous, true, now, 0),
                 ct);
         }
-
-        await _settings.SetAsync("tasks.seeded", "1", ct);
     }
 
     public async ValueTask<Result<TaskRecord>> CreateAsync(TaskInput input, CancellationToken ct)