W17: extract ai_common shared module + fix anthropic data race + brace bugs

- New plugins_upper/ai_common/ static library: shared PluginConfig, ToolCallAccum,
  StreamContext, secure_zero, extract_host_port, serialize_tool_calls, free_chat_result
- Refactored openai/anthropic plugins to use dstalk_ai:: namespace from ai_common
- Fixed anthropic g_config raw pointer → std::atomic (data race)
- Added SSE parse error counter with threshold abort (kMaxSseParseErrors=5)
- Fixed missing closing brace in both plugins' error-body catch block
- Updated test targets: ai_common include path + link, using namespace dstalk_ai
- plugin_loader_test: added stub_unreg + service_registry.cpp for unregister_service
- Includes pre-existing uncommitted changes from prior waves

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

dstalk_core/include/dstalk/dstalk_host.h

@@ -65,6 +65,7 @@ typedef struct {
     /* --- 服务注册表 / service registry --- */
     int  (*register_service)(const char* name, int version, void* vtable);
     void*(*query_service)(const char* name, int min_version);
+    void (*unregister_service)(const char* name);
 
     /* --- 事件总线 / event bus --- */
     int  (*event_subscribe)(int event_type, dstalk_event_handler_fn handler, void* userdata);

dstalk_core/include/dstalk/dstalk_services.h

@@ -15,7 +15,7 @@ extern "C" {
 #endif
 
 /* ---- AI 服务 vtable / AI service vtable ---- */
-/* 以名称如 "ai.openai" 或 "ai.anthropic" 注册 / Registered under names such as "ai.openai" or "ai.anthropic" */
+/* 以名称如 "ai_openai" 或 "ai_anthropic" 注册 / Registered under names such as "ai_openai" or "ai_anthropic" */
 typedef struct {
     /* 配置服务商连接 (base_url, api_key, model 等) / Configure provider connection (base_url, api_key, model, etc.) */
     int (*configure)(const char* provider, const char* base_url,

dstalk_core/src/host.cpp

@@ -94,6 +94,11 @@ namespace {
         return g_service_registry ? g_service_registry->query_service(name, min_version) : nullptr;
     }
 
+    // Unregister a service by name from the global registry (no-op if name is null).
+    void api_unregister_service(const char* name) {
+        if (g_service_registry) g_service_registry->unregister_service(name);
+    }
+
     // 通过全局事件总线订阅指定事件类型的处理函数。
     // Subscribe a handler to a given event type via the global event bus.
     int api_event_subscribe(int event_type, dstalk_event_handler_fn handler, void* userdata) {
@@ -150,6 +155,7 @@ namespace {
     dstalk_host_api_t g_host_api = {
         api_register_service,
         api_query_service,
+        api_unregister_service,
         api_event_subscribe,
         api_event_emit,
         api_event_unsubscribe,
@@ -218,6 +224,9 @@ DSTALK_API int dstalk_init(const char* config_path)
         g_service_registry = new dstalk::ServiceRegistry();
         g_plugin_loader    = new dstalk::PluginLoader();
 
+        // 连接 PluginLoader 和 ServiceRegistry，以便插件卸载时清理服务注册表 / Wire PluginLoader to ServiceRegistry for service cleanup on plugin unload
+        g_plugin_loader->set_service_registry(g_service_registry);
+
         // 加载配置 / Load config
         if (config_path && config_path[0]) {
             if (g_config->load_file(config_path) != 0) {

dstalk_core/src/plugin_loader.cpp

@@ -6,6 +6,7 @@
  */
 
 #include "plugin_loader.hpp"
+#include "service_registry.hpp"
 
 #include <boost/json.hpp>
 
@@ -234,6 +235,17 @@ int PluginLoader::unload_plugin(int plugin_id)
         }
     }
 
+    // 清理该插件在服务注册表中的条目，避免 dll 卸载后 vtable 悬空指针 / Clean up service registry entries to avoid dangling vtable pointers after DLL unload
+    if (service_registry_) {
+        auto svc_it = plugin_services_.find(plugin.name);
+        if (svc_it != plugin_services_.end()) {
+            for (const auto& svc_name : svc_it->second) {
+                service_registry_->unregister_service(svc_name.c_str());
+            }
+            plugin_services_.erase(svc_it);
+        }
+    }
+
     // 卸载DLL / Unload DLL
 #ifdef _WIN32
     FreeLibrary((HMODULE)plugin.handle);
@@ -422,6 +434,13 @@ int PluginLoader::initialize_all(const dstalk_host_api_t* host_api)
 
             if (plugin.info->on_init) {
                 int result;
+
+                // 记录 on_init 前的服务名称快照，用于 on_init 后 diff 出该插件注册的服务 / Snapshot service names before on_init to discover newly registered services after
+                std::vector<std::string> before_svcs;
+                if (service_registry_) {
+                    before_svcs = service_registry_->list_service_names();
+                }
+
                 try {
                     result = plugin.info->on_init(host_api);
                 } catch (const std::exception& e) {
@@ -444,6 +463,17 @@ int PluginLoader::initialize_all(const dstalk_host_api_t* host_api)
                     failed_count++;
                     continue;
                 }
+
+                // 将 on_init 期间新注册的服务归因到当前插件 / Attribute newly registered services to this plugin
+                if (service_registry_) {
+                    std::vector<std::string> after_svcs = service_registry_->list_service_names();
+                    std::unordered_set<std::string> before_set(before_svcs.begin(), before_svcs.end());
+                    for (const auto& svc_name : after_svcs) {
+                        if (before_set.find(svc_name) == before_set.end()) {
+                            plugin_services_[plugin.name].push_back(svc_name);
+                        }
+                    }
+                }
             }
             plugin.initialized = true;
         }
@@ -477,6 +507,13 @@ int PluginLoader::initialize_pending(const dstalk_host_api_t* host_api)
 
             if (plugin.info->on_init) {
                 int result;
+
+                // 记录 on_init 前的服务名称快照，用于 on_init 后 diff 出该插件注册的服务 / Snapshot service names before on_init to discover newly registered services after
+                std::vector<std::string> before_svcs;
+                if (service_registry_) {
+                    before_svcs = service_registry_->list_service_names();
+                }
+
                 try {
                     result = plugin.info->on_init(host_api);
                 } catch (const std::exception& e) {
@@ -491,6 +528,17 @@ int PluginLoader::initialize_pending(const dstalk_host_api_t* host_api)
                 if (result != 0) {
                     return -1;
                 }
+
+                // 将 on_init 期间新注册的服务归因到当前插件 / Attribute newly registered services to this plugin
+                if (service_registry_) {
+                    std::vector<std::string> after_svcs = service_registry_->list_service_names();
+                    std::unordered_set<std::string> before_set(before_svcs.begin(), before_svcs.end());
+                    for (const auto& svc_name : after_svcs) {
+                        if (before_set.find(svc_name) == before_set.end()) {
+                            plugin_services_[plugin.name].push_back(svc_name);
+                        }
+                    }
+                }
             }
             plugin.initialized = true;
             count++;
@@ -537,6 +585,12 @@ void PluginLoader::shutdown_all()
         plugin.initialized = false;
     }
 
+    // 清空服务注册表，避免后续 DLL 卸载后 vtable 悬空指针 / Clear the service registry to prevent dangling vtable pointers after DLL unload
+    if (service_registry_) {
+        service_registry_->clear();
+    }
+    plugin_services_.clear();
+
     // 释放所有 DLL 句柄 / Free all DLL handles
     for (auto& [id, plugin] : plugins_) {
         if (plugin.handle) {

dstalk_core/src/plugin_loader.hpp

@@ -11,10 +11,13 @@
 #include <atomic>
 #include <string>
 #include <unordered_map>
+#include <unordered_set>
 #include <vector>
 
 namespace dstalk {
 
+class ServiceRegistry;
+
 // 描述单个已加载插件：标识、DLL 句柄、信息 vtable 和初始化状态。
 // Describes a single loaded plugin: identity, DLL handle, info vtable, and init state.
 struct PluginInfo {
@@ -60,6 +63,9 @@ public:
     // 获取插件信息 / Get plugin info
     const PluginInfo* get_plugin(int plugin_id) const;
 
+    // 设置服务注册表引用，供卸载插件时清理服务 / Set service registry reference for service cleanup during plugin unload
+    void set_service_registry(ServiceRegistry* sr) { service_registry_ = sr; }
+
 private:
     // 拓扑排序（按依赖顺序） / Topological sort (by dependency order)
     std::vector<int> topological_sort() const;
@@ -71,6 +77,10 @@ private:
     std::unordered_map<int, PluginInfo> plugins_;
     std::atomic<int> next_id_{1};
     const dstalk_host_api_t* host_api_ = nullptr;
+
+    ServiceRegistry* service_registry_ = nullptr;  // 用于卸载时清理服务 / for service cleanup during unload
+    // 插件名称 -> 该插件注册的服务名称列表 / plugin name -> list of service names registered by that plugin
+    std::unordered_map<std::string, std::vector<std::string>> plugin_services_;
 };
 
 } // namespace dstalk

dstalk_core/src/service_registry.cpp

@@ -48,4 +48,23 @@ void ServiceRegistry::unregister_service(const char* name)
     services_.erase(name);
 }
 
+// 列出当前所有已注册服务名称（shared_lock）/ List all currently registered service names (shared_lock).
+std::vector<std::string> ServiceRegistry::list_service_names() const
+{
+    std::shared_lock<std::shared_mutex> lock(mutex_);
+    std::vector<std::string> names;
+    names.reserve(services_.size());
+    for (const auto& [name, _] : services_) {
+        names.push_back(name);
+    }
+    return names;
+}
+
+// 移除所有已注册服务（unique_lock）/ Remove all registered services (unique_lock).
+void ServiceRegistry::clear()
+{
+    std::unique_lock<std::shared_mutex> lock(mutex_);
+    services_.clear();
+}
+
 } // namespace dstalk

dstalk_core/src/service_registry.hpp

@@ -10,6 +10,7 @@
 #include <shared_mutex>
 #include <string>
 #include <unordered_map>
+#include <vector>
 
 namespace dstalk {
 
@@ -32,6 +33,12 @@ public:
     // 注销服务 / Unregister a named service
     void unregister_service(const char* name);
 
+    // 列出所有已注册服务名称（用于 diff/遍历）/ List all currently registered service names (for diff / iteration)
+    std::vector<std::string> list_service_names() const;
+
+    // 清空所有注册服务 / Remove all registered services
+    void clear();
+
 private:
     struct ServiceEntry {
         std::string name;