refactor: unify kubernetes_ table prefix, merge CI/CD models, LLM session support

- Rename container_clusters → kubernetes_clusters, container_topology_layouts → kubernetes_topology_layouts
- LLM: add session_id to chat history for multi-turn conversation support
- CI/CD: add pipeline_id, deploy_type, artifact_url, k8s_cluster_id to AppRelease
- Cleanup: remove deprecated playbook handler, simplify automation models
- Database: optimize auto-migrate model list
- Frontend: AIOps assistant improvements, api.ts updates

backend/internal/models/automation.go

@@ -59,10 +59,10 @@ func (Script) TableName() string {
 	return "ops_scripts"
 }
 
-// TaskExecution 任务执行记录
+// TaskExecution 任务执行记录（cron / script，不含 Ansible；Ansible 走 AnsibleJob）
 type TaskExecution struct {
 	ID         uint           `gorm:"primarykey" json:"id"`
-	TaskType   string         `gorm:"size:32;not null" json:"task_type"` // cron, script, playbook
+	TaskType   string         `gorm:"size:32;not null" json:"task_type"` // cron, script
 	TaskID     uint           `json:"task_id"`
 	TaskName   string         `gorm:"size:128" json:"task_name"`
 	Status     string         `gorm:"size:32;default:pending" json:"status"` // pending, running, success, failed, cancelled
@@ -83,42 +83,6 @@ func (TaskExecution) TableName() string {
 	return "ops_task_executions"
 }
 
-// Playbook Ansible Playbook模型
-type Playbook struct {
-	ID          uint           `gorm:"primarykey" json:"id"`
-	Name        string         `gorm:"size:128;not null" json:"name"`
-	Code        string         `gorm:"size:64;uniqueIndex;not null" json:"code"`
-	Description string         `gorm:"size:500" json:"description"`
-	Content     string         `gorm:"type:text;not null" json:"content"`
-	Category    string         `gorm:"size:64" json:"category"`
-	Tags        string         `gorm:"type:text" json:"tags"` // JSON 数组字符串，如 ["deploy","docker"]
-	Variables   string         `gorm:"type:text" json:"variables"`
-	Inventory   string         `gorm:"type:text" json:"inventory"`
-	Timeout     int            `gorm:"default:600" json:"timeout"`
-	RunCount    int            `gorm:"default:0" json:"run_count"`
-	CreatedBy   uint           `json:"created_by"`
-	UpdatedBy   uint           `json:"updated_by"`
-	CreatedAt   time.Time      `json:"created_at"`
-	UpdatedAt   time.Time      `json:"updated_at"`
-}
-
-// TableName 表名
-func (Playbook) TableName() string {
-	return "ops_playbooks"
-}
-
-// CreatePlaybookRequest 创建Playbook请求
-type CreatePlaybookRequest struct {
-	Name        string `json:"name" binding:"required"`
-	Description string `json:"description"`
-	Content     string `json:"content" binding:"required"`
-	Category    string `json:"category"`
-	Tags        string `json:"tags"` // JSON 数组字符串
-	Variables   string `json:"variables"`
-	Inventory   string `json:"inventory"`
-	Timeout     int    `json:"timeout"`
-}
-
 // CreateCronJobRequest 创建定时任务请求
 type CreateCronJobRequest struct {
 	Name        string   `json:"name" binding:"required"`