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/OnDemandTestsTests.cs

@@ -25,7 +25,7 @@ public sealed class OnDemandTestsTests
     private async Task<AgentSimulator> AgentWithProbeAsync()
     {
         AgentSimulator agent = await _backend.ConnectAgentAsync();
-        await agent.WaitForTaskSetAsync(s => s.Tasks.Count == 2);
+        await agent.WaitForTaskSetAsync(s => s.Tasks.Count == Defaults.TaskCount);
         await agent.SendEventAsync(AgentEventKinds.ProbeConnected, _backend.DefaultProbeId);
         await BackendFixture.EventuallyAsync(async () => (await _backend.GetJsonAsync(_backend.Admin, "/api/admin/agents/" + agent.NodeId.Value))["probe_connected"]!.GetValue<bool>());
         return agent;
@@ -37,7 +37,7 @@ public sealed class OnDemandTestsTests
     public async Task Start_RequiresAProbeSession_APlanThatExists_AndValidParams()
     {
         await using AgentSimulator agent = await _backend.ConnectAgentAsync();
-        await agent.WaitForTaskSetAsync(s => s.Tasks.Count == 2);
+        await agent.WaitForTaskSetAsync(s => s.Tasks.Count == Defaults.TaskCount);
 
         using HttpResponseMessage offline = await StartAsync(agent, Plan("hy2_ladder"));
         Assert.Equal(HttpStatusCode.Conflict, offline.StatusCode);