feat: Round 5 - Memory Service, Tool Engine, Call Records, Thinking Logs

- Fix: Session history flash (race condition + WS guard)
- Fix: Chat background overlay + sidebar transparency
- Fix: IoT device control (Chinese action names, status field)
- Feat: Independent memory-service (port 8091, 13 endpoints)
- Feat: Independent tool-engine service (port 8092, 13 tools)
- Feat: Tool call logs with paginated DevTools panel
- Feat: Thinking log records with DevTools panel
- Feat: Future development roadmap document
- Chore: Updated .gitignore, go.work, DevTools config
- Chore: 5-service health check, project review docs

backend/tool-engine/internal/tools/registry.go

@@ -0,0 +1,41 @@
+package tools
+
+import (
+	"context"
+
+	"github.com/yourname/cyrene-ai/tool-engine/internal/model"
+)
+
+// Tool 工具接口
+type Tool interface {
+	Definition() model.ToolDefinition
+	Execute(ctx context.Context, arguments map[string]interface{}) (*model.ToolResult, error)
+}
+
+// IoTClientFactory 用于创建 IoT 客户端的工厂函数类型
+type IoTClientFactory func() IoTClientInterface
+
+// IoTClientInterface IoT 客户端接口（解耦对 ai-core 的依赖）
+type IoTClientInterface interface {
+	GetAllDevices() ([]IoTDevice, error)
+	GetDevice(id string) (*IoTDevice, error)
+	ToggleDevice(id string) error
+	SetDeviceProperty(id string, field string, value interface{}) error
+}
+
+// IoTDevice IoT 设备结构体
+type IoTDevice struct {
+	ID          string  `json:"id"`
+	Name        string  `json:"name"`
+	Type        string  `json:"type"`
+	Status      string  `json:"status"`
+	Brightness  int     `json:"brightness,omitempty"`
+	Color       string  `json:"color,omitempty"`
+	Temperature float64 `json:"temperature,omitempty"`
+	Mode        string  `json:"mode,omitempty"`
+	Position    int     `json:"position,omitempty"`
+	Value       float64 `json:"value,omitempty"`
+	Unit        string  `json:"unit,omitempty"`
+	Battery     int     `json:"battery,omitempty"`
+	LastUpdated string  `json:"last_updated"`
+}