refactor!: rename the project from Monitor to MoShiro [CI]

Namespaces, assemblies, solution, binaries, images, systemd units, config paths, environment variables, protocol methods and the Linux user are all renamed. Breaking: existing databases, node identities and installed units must be recreated.

backend/src/MoShiro.Backend/BackendHost.cs

@@ -0,0 +1,65 @@
+using Fleet.Server;
+using Microsoft.AspNetCore.Builder;
+using Microsoft.Extensions.Configuration;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Logging;
+using MoShiro.Backend.Api;
+using MoShiro.Backend.Application;
+using MoShiro.Backend.Gateway;
+using MoShiro.Backend.Storage.Sqlite;
+
+namespace MoShiro.Backend;
+
+/// <summary>
+/// 组合根：在这里显式注册所有层。配置来自 <c>appsettings.json</c>、环境变量（<c>MoShiro__DataDirectory</c> 等）和命令行。
+/// 测试用 <see cref="Build"/> 在真实端口上启动整个后端。
+/// </summary>
+public static class BackendHost
+{
+    public const string ConfigurationSection = "MoShiro";
+    public const int MaxRequestBodyBytes = 64 * 1024;
+
+    public static WebApplication Build(string[] args, Action<BackendOptions>? configureOptions = null, TimeProvider? time = null)
+    {
+        WebApplicationBuilder builder = WebApplication.CreateSlimBuilder(args);
+
+        var options = new BackendOptions();
+        builder.Configuration.GetSection(ConfigurationSection).Bind(options);
+        configureOptions?.Invoke(options);
+
+        builder.WebHost.ConfigureKestrel(kestrel => kestrel.Limits.MaxRequestBodySize = MaxRequestBodyBytes);
+        builder.Logging.AddSimpleConsole(console =>
+        {
+            console.SingleLine = true;
+            console.UseUtcTimestamp = true;
+            console.TimestampFormat = "yyyy-MM-ddTHH:mm:ss.fffZ ";
+        });
+
+        IServiceCollection services = builder.Services;
+        services.AddSingleton(time ?? TimeProvider.System);
+        services.AddMoShiroSqlite(options.DataDirectory);
+        // 国家和运营商：Backend 用节点的来源地址查一次（Probe、Agent 不访问任何外部服务）；地址留空就不查
+        if (string.IsNullOrWhiteSpace(options.GeoLookupUrl))
+        {
+            services.AddSingleton<IGeoLookup, NoGeoLookup>();
+        }
+        else
+        {
+            services.AddSingleton<IGeoLookup>(new HttpGeoLookup(options.GeoLookupUrl));
+        }
+
+        services.AddMoShiroApplication(options);
+        services.AddMoShiroGateway();
+        services.AddMoShiroApi();
+
+        WebApplication app = builder.Build();
+        // 静默死亡的 Agent（断电、断网）不会关闭连接：15 秒一个 Ping，20 秒没有 Pong 就关闭，这样面板上的在线状态才可信
+        app.UseWebSockets(new WebSocketOptions { KeepAliveInterval = TimeSpan.FromSeconds(15), KeepAliveTimeout = TimeSpan.FromSeconds(20) });
+        app.UseMoShiroCors(options.CorsOrigins);
+        app.UseMoShiroApi();
+        app.MapMoShiroApi();
+        app.MapFleetEnrollment("/api/agent/v1/enroll");
+        app.MapFleetLink("/api/agent/v1/rpc");
+        return app;
+    }
+}