feat: Phase 3 插件与工具系统 — Plugin SDK + Plugin Manager + 13内置插件 (40文件, 3293行)

- Plugin SDK: Plugin/Tool/ComplexTool/HostAPI 标准化接口
- Plugin Manager: 插件生命周期管理 (Install/Enable/Disable/Uninstall/Reload)
- Tool Registry: 聚合工具注册表 (Register/Execute/Dispatch)
- 13 个内置插件: 将原有硬编码工具迁移为标准插件格式
- REST API: 11 个端点 (net/http, 零外部依赖)
- ai-core 集成: PluginManagerClient 替代本地工具调用
- plugin.json 元数据: 每个插件含完整 author/version/category/permissions

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

backend/plugin-manager/internal/manager/registry.go

@@ -0,0 +1,85 @@
+package manager
+
+import (
+	"context"
+	"fmt"
+	"sync"
+
+	"github.com/yourname/cyrene-ai/plugin-manager/internal/sdk"
+)
+
+// ToolRegistry aggregates tool definitions from all running plugins and dispatches execution.
+type ToolRegistry struct {
+	mu    sync.RWMutex
+	tools map[string]sdk.Tool // tool ID -> Tool
+}
+
+func NewToolRegistry() *ToolRegistry {
+	return &ToolRegistry{tools: make(map[string]sdk.Tool)}
+}
+
+func (r *ToolRegistry) Register(tool sdk.Tool) error {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+	id := tool.Definition().ID
+	if _, exists := r.tools[id]; exists {
+		return fmt.Errorf("tool %q already registered", id)
+	}
+	r.tools[id] = tool
+	return nil
+}
+
+func (r *ToolRegistry) Unregister(toolID string) {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+	delete(r.tools, toolID)
+}
+
+func (r *ToolRegistry) Get(toolID string) (sdk.Tool, bool) {
+	r.mu.RLock()
+	defer r.mu.RUnlock()
+	t, ok := r.tools[toolID]
+	return t, ok
+}
+
+func (r *ToolRegistry) List() []sdk.Tool {
+	r.mu.RLock()
+	defer r.mu.RUnlock()
+	result := make([]sdk.Tool, 0, len(r.tools))
+	for _, t := range r.tools {
+		result = append(result, t)
+	}
+	return result
+}
+
+func (r *ToolRegistry) Definitions() []sdk.ToolDefinition {
+	r.mu.RLock()
+	defer r.mu.RUnlock()
+	defs := make([]sdk.ToolDefinition, 0, len(r.tools))
+	for _, t := range r.tools {
+		defs = append(defs, t.Definition())
+	}
+	return defs
+}
+
+func (r *ToolRegistry) Execute(ctx context.Context, toolID string, args map[string]interface{}) (*sdk.ToolResult, error) {
+	r.mu.RLock()
+	tool, ok := r.tools[toolID]
+	r.mu.RUnlock()
+	if !ok {
+		return nil, fmt.Errorf("tool %q not found", toolID)
+	}
+	if err := tool.Validate(args); err != nil {
+		return &sdk.ToolResult{Success: false, Error: err.Error()}, nil
+	}
+	return tool.Execute(ctx, args)
+}
+
+// UnregisterAll removes all tools matching a prefix (plugin's tools).
+func (r *ToolRegistry) UnregisterAll(toolIDs []string) {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+	for _, id := range toolIDs {
+		delete(r.tools, id)
+	}
+}