feat: implement chat and conversation history management with database schema and API endpoints

internal/dtos/response/chatbot.go

@@ -0,0 +1,18 @@
+package response
+
+import (
+	"time"
+)
+
+type ChatbotHistoryDto struct {
+	ID        string     `json:"id"`
+	UserID    string     `json:"user_id"`
+	Question  string     `json:"question"`
+	Answer    string     `json:"answer"`
+	CreatedAt *time.Time `json:"created_at,omitempty"`
+}
+
+type GetChatbotHistoryResponse struct {
+	Items     []*ChatbotHistoryDto `json:"items"`
+	PreCursor string               `json:"pre_cursor,omitempty"`
+}