部署：bubblewrap 沙箱、编译检查、访问口令、Docker Compose

- 学生程序每次运行放进 bubblewrap：断网，只读挂载系统文件、运行时和自己的工程目录，
  看不到其他进程和服务器环境变量；限制堆内存 128 MB、CPU 时间 120 秒、运行 60 分钟，
  nice 10，全站同时运行上限 150；启动时自检沙箱，不可用时拒绝运行
- 编译检查（SIM001）：网络、反射、启动进程、调用本机代码、加载程序集、dynamic 给出中文报错
- 访问口令：cookie 保存口令哈希，按真实 IP 限制输错次数；前端口令页
- 服务端配置集中到 config.ts，可用环境变量覆盖；Bun 直接提供打包好的网页
- Dockerfile（多阶段，服务端打包成单文件）、compose.yaml（Caddy 只收 HTTP，接入 NPM 的
  npm_proxy 网络）、deploy/deploy.sh（本机构建后经 ssh 传到服务器）和部署说明
- 测试：沙箱隔离、内存上限、CPU 时间上限、编译检查

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

runtime/Sim.Runner/ApiPolicy.cs

@@ -0,0 +1,96 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.CSharp;
+using Microsoft.CodeAnalysis.CSharp.Syntax;
+
+namespace Sim.Runner;
+
+/// <summary>
+/// 编译时检查学生代码用到的 API：网络、启动外部程序、反射、调用本机代码等课程用不到、只会带来风险的功能，
+/// 直接给出中文报错。真正的隔离靠运行时沙箱，这里是第二道防线，也让学生看到明确的原因。
+/// </summary>
+internal static class ApiPolicy
+{
+#pragma warning disable RS2008 // 不是分析器，不需要发布跟踪
+    private static readonly DiagnosticDescriptor NotAllowed = new(
+        "SIM001", "平台不允许使用的功能", "平台不允许使用 {0}（{1}）", "Usage", DiagnosticSeverity.Error, isEnabledByDefault: true);
+#pragma warning restore RS2008
+
+    /// <summary>整个命名空间（含子命名空间）都不允许</summary>
+    private static readonly (string Namespace, string Reason)[] DeniedNamespaces =
+    {
+        ("System.Net", "网络访问"),
+        ("System.Reflection", "反射"),
+        ("System.Runtime.Loader", "加载程序集"),
+        ("System.IO.Pipes", "进程间通信"),
+        ("System.IO.MemoryMappedFiles", "进程间通信"),
+    };
+
+    /// <summary>单个类型不允许（所在命名空间的其他类型可以用）</summary>
+    private static readonly Dictionary<string, string> DeniedTypes = new()
+    {
+        ["System.Diagnostics.Process"] = "启动其他程序",
+        ["System.Diagnostics.ProcessStartInfo"] = "启动其他程序",
+        ["System.AppDomain"] = "加载程序集",
+        ["System.Runtime.InteropServices.Marshal"] = "调用本机代码",
+        ["System.Runtime.InteropServices.DllImportAttribute"] = "调用本机代码",
+        ["System.Runtime.InteropServices.LibraryImportAttribute"] = "调用本机代码",
+        ["System.Runtime.InteropServices.NativeLibrary"] = "调用本机代码",
+        ["System.Runtime.InteropServices.NativeMemory"] = "调用本机代码",
+    };
+
+    public static IEnumerable<Diagnostic> Check(CSharpCompilation compilation)
+    {
+        foreach (var tree in compilation.SyntaxTrees)
+        {
+            var model = compilation.GetSemanticModel(tree);
+            foreach (var name in tree.GetRoot().DescendantNodes().OfType<SimpleNameSyntax>())
+            {
+                // A.B.C 只检查最右边的名字，避免同一处报好几次
+                if (name.Parent is QualifiedNameSyntax q && q.Left == name) continue;
+                // var 推断出的类型在初始化表达式里已经检查过
+                if (name is IdentifierNameSyntax { IsVar: true }) continue;
+                if (name.Parent is MemberAccessExpressionSyntax m && m.Expression == name && model.GetSymbolInfo(name).Symbol is INamespaceOrTypeSymbol) continue;
+
+                var symbol = model.GetSymbolInfo(name).Symbol;
+                if (symbol == null) continue;
+                if (Reason(symbol) is { } reason)
+                {
+                    yield return Diagnostic.Create(NotAllowed, name.GetLocation(), Display(symbol), reason);
+                }
+            }
+        }
+    }
+
+    private static string? Reason(ISymbol symbol)
+    {
+        if (symbol is IDynamicTypeSymbol) return "dynamic 动态调用";
+        // using 指令里的命名空间不算：VS 生成的 AssemblyInfo.cs 会 using System.Runtime.InteropServices
+        if (symbol is INamespaceSymbol) return null;
+        var type = symbol as INamedTypeSymbol ?? symbol.ContainingType;
+        // 方法的返回值、参数类型由调用处检查；这里看符号本身属于哪个类型
+        for (var t = type; t != null; t = t.ContainingType)
+        {
+            var fullName = t.OriginalDefinition.ToDisplayString(SymbolDisplayFormat.FullyQualifiedFormat).Replace("global::", "");
+            if (DeniedTypes.TryGetValue(fullName, out var reason)) return reason;
+        }
+        if (type == null) return null;
+        // AssemblyInfo.cs 里的 [assembly: AssemblyTitle(...)] 等特性可以用
+        if (type.Name.EndsWith("Attribute") && type.ContainingNamespace.ToDisplayString() == "System.Reflection") return null;
+        var ns = type.ContainingNamespace.ToDisplayString();
+        foreach (var (denied, reason) in DeniedNamespaces)
+        {
+            if (ns == denied || ns.StartsWith(denied + ".")) return reason;
+        }
+        return null;
+    }
+
+    private static string Display(ISymbol symbol) => symbol switch
+    {
+        IDynamicTypeSymbol => "dynamic",
+        INamedTypeSymbol type => type.ToDisplayString(),
+        _ => $"{symbol.ContainingType.ToDisplayString()}.{symbol.Name}",
+    };
+}

runtime/Sim.Runner/StudentCompiler.cs

@@ -55,15 +55,16 @@ internal static class StudentCompiler
         using var pdbStream = new MemoryStream();
         var emit = compilation.Emit(peStream, pdbStream,
             options: new EmitOptions(debugInformationFormat: DebugInformationFormat.PortablePdb));
+        var denied = ApiPolicy.Check(compilation).ToList();
 
         var diagnostics = new JsonArray();
-        foreach (var diagnostic in emit.Diagnostics
+        foreach (var diagnostic in emit.Diagnostics.Concat(denied)
                      .Where(d => d.Severity is DiagnosticSeverity.Error or DiagnosticSeverity.Warning)
                      .OrderBy(d => d.Severity == DiagnosticSeverity.Error ? 0 : 1))
         {
             diagnostics.Add(ToJson(diagnostic));
         }
-        return new Result(emit.Success, peStream.ToArray(), pdbStream.ToArray(), diagnostics);
+        return new Result(emit.Success && denied.Count == 0, peStream.ToArray(), pdbStream.ToArray(), diagnostics);
     }
 
     private static JsonObject ToJson(Diagnostic diagnostic)