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/tests/MoShiro.Backend.Tests/PersistenceTests.cs

@@ -57,7 +57,7 @@ public sealed class PersistenceTests : IAsyncLifetime
 
         // 同一个身份可以重新连接，并拿回当前版本的期望状态
         await using AgentSimulator again = await _backend.ReconnectAsync(agent);
-        Assert.NotNull(await again.WaitForTaskSetAsync(s => s.Tasks.Count == 2));
+        Assert.NotNull(await again.WaitForTaskSetAsync(s => s.Tasks.Count == Defaults.TaskCount));
 
         // 已经落盘的块在重启后仍然可以按 ID 下载
         JsonNode chunks = await _backend.GetJsonAsync(admin, $"/api/admin/raw/chunks?agent_id={id}&limit=1");