feat(cordis): 完成阶段5访问介导与诊断

Assets/Modules/ShrinkContext.Core/Runtime/Context/ShrinkCtx.cs

@@ -15,14 +15,17 @@ namespace ShrinkContext
     {
         private readonly List<ShrinkEffectHandle> _effects = new();
         private readonly Dictionary<string, string>? _isolateOverlay;
+        private Dictionary<string, IReadOnlyDictionary<string, object?>>? _interceptOverlay;
 
         internal ShrinkCtx(ShrinkContextRuntime runtime, ShrinkCtx? parent, ShrinkFiber? ownerFiber,
-            Dictionary<string, string>? isolateOverlay)
+            Dictionary<string, string>? isolateOverlay,
+            IReadOnlyDictionary<string, IReadOnlyDictionary<string, object?>>? interceptOverlay = null)
         {
             Runtime = runtime;
             Parent = parent;
             OwnerFiber = ownerFiber;
             _isolateOverlay = isolateOverlay;
+            ReplaceIntercept(interceptOverlay);
         }
 
         public ShrinkContextRuntime Runtime { get; }
@@ -106,7 +109,17 @@ namespace ShrinkContext
         /// 提供依赖（set 是可逆效应）：立即安装绑定并通知依赖者；
         /// 逆操作撤回绑定并再次通知。句柄同时挂在当前上下文上，随上下文卸载自动撤回。
         /// </summary>
-        public ShrinkEffectHandle Set<T>(string key, T value) => Runtime.SetBinding(this, key, value);
+        public ShrinkEffectHandle Set<T>(string key, T value) => Runtime.SetBinding(this, key, value, null);
+
+        /// <summary>提供带访问策略的依赖；策略只在介导 Get 时运行，原始编排查找不会运行策略。</summary>
+        public ShrinkEffectHandle Set<T>(string key, T value, IShrinkCoeffectAccessPolicy accessPolicy) =>
+            Runtime.SetBinding(this, key, value, accessPolicy ?? throw new ArgumentNullException(nameof(accessPolicy)));
+
+        public ShrinkEffectHandle Set<T>(ShrinkKey<T> key, T value) =>
+            Set((key ?? throw new ArgumentNullException(nameof(key))).Id, value);
+
+        public ShrinkEffectHandle Set<T>(ShrinkKey<T> key, T value, IShrinkCoeffectAccessPolicy accessPolicy) =>
+            Set((key ?? throw new ArgumentNullException(nameof(key))).Id, value, accessPolicy);
 
         /// <summary>
         /// 代理介导的依赖访问（论文算法 6）：沿纤程链解析已提交视图；
@@ -119,7 +132,7 @@ namespace ShrinkContext
             while (fiber != null)
             {
                 if (fiber.Committed != null && fiber.Committed.TryGetValue(key, out var binding))
-                    return (T)binding.Value!;
+                    return Runtime.ResolveAccess<T>(this, key, binding);
                 if (fiber.InjectSet.Contains(key))
                     throw new ShrinkInactiveAccessException(key, fiber.Name);
                 fiber = fiber.Parent;
@@ -128,6 +141,9 @@ namespace ShrinkContext
             throw new ShrinkUndeclaredAccessException(key);
         }
 
+        public T Get<T>(ShrinkKey<T> key) => Get<T>(
+            (key ?? throw new ArgumentNullException(nameof(key))).Id);
+
         /// <summary>与 <see cref="Get{T}"/> 相同的介导规则；未激活返回 false 而不抛异常。</summary>
         public bool TryGet<T>(string key, out T value)
         {
@@ -136,7 +152,7 @@ namespace ShrinkContext
             {
                 if (fiber.Committed != null && fiber.Committed.TryGetValue(key, out var binding))
                 {
-                    value = (T)binding.Value!;
+                    value = Runtime.ResolveAccess<T>(this, key, binding);
                     return true;
                 }
                 if (fiber.InjectSet.Contains(key))
@@ -148,6 +164,9 @@ namespace ShrinkContext
             return false;
         }
 
+        public bool TryGet<T>(ShrinkKey<T> key, out T value) => TryGet(
+            (key ?? throw new ArgumentNullException(nameof(key))).Id, out value);
+
         /// <summary>
         /// 派生隔离子上下文（论文定义 28/29 的派生实现）：
         /// 覆盖 key 的 realm 解析；父上下文不受影响；丢弃子上下文即隐式恢复。
@@ -162,6 +181,33 @@ namespace ShrinkContext
             return new ShrinkCtx(Runtime, this, OwnerFiber, new Dictionary<string, string> { [key] = realm });
         }
 
+        public ShrinkCtx Isolate<T>(ShrinkKey<T> key, string realm) => Isolate(
+            (key ?? throw new ArgumentNullException(nameof(key))).Id, realm);
+
+        /// <summary>
+        /// 派生带拦截元数据的子上下文。子级同名 metadata 覆盖父级；丢弃子上下文即恢复。
+        /// 该操作不改变 realm、provider 或 target，因此不会触发 fiber 重载。
+        /// </summary>
+        public ShrinkCtx Intercept(string key, IReadOnlyDictionary<string, object?> metadata)
+        {
+            if (string.IsNullOrWhiteSpace(key))
+                throw new ArgumentException("Key must not be null or empty.", nameof(key));
+            if (metadata == null)
+                throw new ArgumentNullException(nameof(metadata));
+
+            var metadataCopy = new Dictionary<string, object?>(StringComparer.Ordinal);
+            foreach (var pair in metadata)
+                metadataCopy[pair.Key] = pair.Value;
+            var overlay = new Dictionary<string, IReadOnlyDictionary<string, object?>>(StringComparer.Ordinal)
+            {
+                [key] = metadataCopy
+            };
+            return new ShrinkCtx(Runtime, this, OwnerFiber, null, overlay);
+        }
+
+        public ShrinkCtx Intercept<T>(ShrinkKey<T> key, IReadOnlyDictionary<string, object?> metadata) =>
+            Intercept((key ?? throw new ArgumentNullException(nameof(key))).Id, metadata);
+
         internal ShrinkCtx CreateChildForFiber(ShrinkFiber fiber) => new(Runtime, this, fiber, null);
 
         /// <summary>在派生子上下文中叠加隔离覆盖（同键后者优先），供加载器为条目配置隔离域。</summary>
@@ -180,6 +226,38 @@ namespace ShrinkContext
             return new ShrinkCtx(Runtime, this, OwnerFiber, overlay);
         }
 
+        /// <summary>在当前纤程上下文上叠加 loader 条目配置的 intercept。</summary>
+        internal ShrinkCtx WithIntercept(
+            IReadOnlyDictionary<string, IReadOnlyDictionary<string, object?>> intercept) =>
+            new(Runtime, this, OwnerFiber, null, interceptOverlay: intercept);
+
+        /// <summary>原地替换本层 intercept，供 loader 在不重载 fiber 的情况下更新访问策略。</summary>
+        internal void ReplaceIntercept(
+            IReadOnlyDictionary<string, IReadOnlyDictionary<string, object?>>? intercept)
+        {
+            if (intercept == null || intercept.Count == 0)
+            {
+                _interceptOverlay = null;
+                return;
+            }
+
+            var copy = new Dictionary<string, IReadOnlyDictionary<string, object?>>(StringComparer.Ordinal);
+            foreach (var pair in intercept)
+            {
+                if (string.IsNullOrWhiteSpace(pair.Key))
+                    throw new ArgumentException("Intercept key must not be empty.", nameof(intercept));
+                if (pair.Value == null)
+                    throw new ArgumentException($"Intercept metadata for '{pair.Key}' must not be null.",
+                        nameof(intercept));
+                var metadataCopy = new Dictionary<string, object?>(StringComparer.Ordinal);
+                foreach (var metadataPair in pair.Value)
+                    metadataCopy[metadataPair.Key] = metadataPair.Value;
+                copy[pair.Key] = metadataCopy;
+            }
+
+            _interceptOverlay = copy;
+        }
+
         /// <summary>解析 key 在本上下文中归属的 realm：沿父链找最近的隔离覆盖，默认 realm 为 key 自身。</summary>
         internal string ResolveRealm(string key)
         {
@@ -193,5 +271,30 @@ namespace ShrinkContext
 
             return key;
         }
+
+        /// <summary>按根到叶顺序合并拦截元数据；越接近访问方的上下文优先。</summary>
+        internal IReadOnlyDictionary<string, object?> ResolveInterceptMetadata(string key)
+        {
+            var chain = new Stack<ShrinkCtx>();
+            for (var current = this; current != null; current = current.Parent)
+                chain.Push(current);
+
+            var merged = new Dictionary<string, object?>(StringComparer.Ordinal);
+            while (chain.Count > 0)
+            {
+                var current = chain.Pop();
+                if (current._interceptOverlay == null ||
+                    !current._interceptOverlay.TryGetValue(key, out var metadata))
+                    continue;
+
+                foreach (var pair in metadata)
+                    merged[pair.Key] = pair.Value;
+            }
+
+            return merged;
+        }
+
+        internal IReadOnlyCollection<string> GetLocalInterceptKeys() =>
+            _interceptOverlay?.Keys ?? (IReadOnlyCollection<string>)Array.Empty<string>();
     }
 }