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/AgentEndToEndTests.cs

@@ -44,7 +44,7 @@ public sealed class AgentEndToEndTests
     {
         // 默认模板的端口（7443/7444）不在这个 Agent 实际监听的端口里：任务被拒绝，原因是 policy_denied
         await using AgentHarness agent = await AgentHarness.StartAsync(_backend);
-        await BackendFixture.EventuallyAsync(async () => (await AgentViewAsync(agent))["rejected"]!.AsArray().Count == 2);
+        await BackendFixture.EventuallyAsync(async () => (await AgentViewAsync(agent))["rejected"]!.AsArray().Count == Defaults.TaskCount);
         JsonNode rejected = (await AgentViewAsync(agent))["rejected"]!;
         Assert.All(rejected.AsArray(), item => Assert.Equal("policy_denied", item!["reason"]!.GetValue<string>()));