diff --git a/.github/workflows/cd.yaml b/.github/workflows/cd.yaml
index 55c91474..e349a1dc 100644
--- a/.github/workflows/cd.yaml
+++ b/.github/workflows/cd.yaml
@@ -55,12 +55,6 @@ jobs:
     runs-on: [self-hosted, harbor, k8s]
     timeout-minutes: 1
     steps:
-      # Phase 16: 清理 Runner diag logs 避免 "file already exists" 錯誤
-      - name: Clean runner diag logs
-        run: |
-          rm -f ~/actions-runner-awoooi/_diag/pages/*.log 2>/dev/null || true
-          rm -f ~/actions-runner-awoooi-2/_diag/pages/*.log 2>/dev/null || true
-
       - name: "Check Required Secrets"
         run: |
           MISSING=""
diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index 5a2b21bb..39ce6dcb 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -31,12 +31,6 @@ jobs:
     runs-on: [self-hosted, harbor, k8s]
     timeout-minutes: 1
     steps:
-      # Phase 16: 清理 Runner diag logs 避免 "file already exists" 錯誤
-      - name: Clean runner diag logs
-        run: |
-          rm -f ~/actions-runner-awoooi/_diag/pages/*.log 2>/dev/null || true
-          rm -f ~/actions-runner-awoooi-2/_diag/pages/*.log 2>/dev/null || true
-
       - name: Quick sanity check
         run: |
           echo "✅ Runner 可用"
@@ -50,13 +44,14 @@ jobs:
     needs: pre-flight
     timeout-minutes: 10
     steps:
-      - name: Clean worktrees
-        run: rm -rf .claude/worktrees 2>/dev/null || true
-
       - uses: actions/checkout@v4
         with:
           clean: true
 
+      # 清理 worktrees (在 checkout 後，確保在 workspace 內)
+      - name: Clean worktrees
+        run: rm -rf ${{ github.workspace }}/.claude/worktrees 2>/dev/null || true
+
       - name: Setup pnpm
         uses: pnpm/action-setup@v3
         with:
diff --git a/apps/api/src/api/v1/approvals.py b/apps/api/src/api/v1/approvals.py
index 09010560..96390dc7 100644
--- a/apps/api/src/api/v1/approvals.py
+++ b/apps/api/src/api/v1/approvals.py
@@ -21,12 +21,8 @@ Endpoints:
 """
 
 import asyncio
-from typing import TYPE_CHECKING
 from uuid import UUID
 
-if TYPE_CHECKING:
-    from src.services.notifications import ExecutionStatus
-
 from fastapi import (
     APIRouter,
     BackgroundTasks,
@@ -54,8 +50,8 @@ from src.models.approval import (
     SignResponse,
 )
 from src.services.approval_db import get_approval_service, get_timeline_service
+from src.services.approval_execution import get_execution_service
 from src.services.executor import get_executor
-from src.services.operation_parser import parse_operation_from_action
 from src.services.proposal_service import get_proposal_service
 
 router = APIRouter(prefix="/approvals", tags=["HITL Approvals"])
@@ -161,209 +157,10 @@ async def test_k8s_connection() -> dict:
 
 
 # =============================================================================
-# Background Execution Helper
-# Phase 16 R4: parse_operation_from_action 已抽取至 src/services/operation_parser.py
+# Phase 16 R4.2: 執行邏輯已抽取至 src/services/approval_execution.py
 # =============================================================================
 
 
-async def execute_approved_action(approval: ApprovalRequest) -> None:
-    """
-    背景執行已批准的操作
-
-    此函數由 BackgroundTasks 呼叫，不阻塞 API 回應
-    Phase 5: 執行後更新資料庫狀態
-    Phase 6: 執行後發送通知 (Post-Execution Hook)
-    """
-    from src.services.notifications import (
-        ExecutionStatus,
-    )
-
-    logger.info(
-        "background_execution_start",
-        approval_id=str(approval.id),
-        action=approval.action,
-    )
-
-    service = get_approval_service()
-    timeline = get_timeline_service()
-
-    # Parse operation details (Phase 16 R4: 使用新的 ParsedOperation dataclass)
-    parsed = parse_operation_from_action(approval.action)
-    operation_type = parsed.operation_type
-    resource_name = parsed.resource_name
-    namespace = parsed.namespace
-
-    if operation_type is None or resource_name is None:
-        logger.warning(
-            "background_execution_skip",
-            approval_id=str(approval.id),
-            reason="Could not parse operation type from action",
-            action=approval.action,
-        )
-        # Phase 5: 更新資料庫狀態
-        await service.update_execution_status(approval.id, success=False)
-        await timeline.add_event(
-            event_type="exec",
-            status="error",
-            title="執行失敗: 無法解析操作類型",
-            description=f"Action: {approval.action}",
-            actor="leWOOOgo",
-            actor_role="executor",
-            approval_id=str(approval.id),
-        )
-
-        # Phase 6: 發送失敗通知 (fire-and-forget, 不阻塞執行緒)
-        asyncio.create_task(_send_execution_notification(
-            approval=approval,
-            execution_status=ExecutionStatus.FAILED,
-            operation_type="unknown",
-            namespace=namespace,
-            error_message="Could not parse operation type",
-        ))
-        return
-
-    # Execute with audit
-    executor = get_executor()
-    result = await executor.execute_with_audit(
-        approval=approval,
-        operation_type=operation_type,
-        resource_name=resource_name,
-        namespace=namespace,
-    )
-
-    # Phase 5: 更新資料庫狀態
-    await service.update_execution_status(approval.id, success=result.success)
-
-    # Update approval status based on result
-    if result.success:
-        logger.info(
-            "background_execution_success",
-            approval_id=str(approval.id),
-            operation=operation_type.value,
-            target=resource_name,
-            namespace=namespace,
-            duration_ms=result.duration_ms,
-        )
-        await timeline.add_event(
-            event_type="exec",
-            status="success",
-            title=f"✅ K8s 執行成功: {operation_type.value}",
-            description=f"Target: {resource_name} @ {namespace} ({result.duration_ms}ms)",
-            actor="leWOOOgo",
-            actor_role="executor",
-            approval_id=str(approval.id),
-        )
-
-        # Phase 6: 發送成功通知 (fire-and-forget, 不阻塞執行緒)
-        asyncio.create_task(_send_execution_notification(
-            approval=approval,
-            execution_status=ExecutionStatus.SUCCESS,
-            operation_type=operation_type.value,
-            namespace=namespace,
-            duration_ms=result.duration_ms,
-        ))
-    else:
-        logger.error(
-            "background_execution_failed",
-            approval_id=str(approval.id),
-            operation=operation_type.value,
-            target=resource_name,
-            namespace=namespace,
-            error=result.error,
-        )
-        await timeline.add_event(
-            event_type="exec",
-            status="error",
-            title=f"❌ K8s 執行失敗: {operation_type.value}",
-            description=f"Error: {result.error}",
-            actor="leWOOOgo",
-            actor_role="executor",
-            approval_id=str(approval.id),
-        )
-
-        # Phase 6: 發送失敗通知 (fire-and-forget, 包含 Dry-Run 攔截)
-        exec_status = ExecutionStatus.DRY_RUN_BLOCKED if "not found" in (result.error or "") else ExecutionStatus.FAILED
-        asyncio.create_task(_send_execution_notification(
-            approval=approval,
-            execution_status=exec_status,
-            operation_type=operation_type.value,
-            namespace=namespace,
-            error_message=result.error,
-            duration_ms=result.duration_ms,
-        ))
-
-
-async def _send_execution_notification(
-    approval: ApprovalRequest,
-    execution_status: "ExecutionStatus",
-    operation_type: str,
-    namespace: str,
-    duration_ms: int | None = None,
-    error_message: str | None = None,
-) -> None:
-    """
-    Phase 6: 發送執行通知 (Post-Execution Hook)
-
-    將執行結果發送至所有已配置的通知頻道 (Discord, Slack, etc.)
-    """
-    from src.core.config import settings
-    from src.services.notifications import (
-        NotificationMessage,
-        get_notification_manager,
-    )
-
-    if not settings.NOTIFICATION_ENABLED:
-        logger.info("notification_disabled", approval_id=str(approval.id))
-        return
-
-    try:
-        # 建構簽核者列表
-        signers = [
-            {"name": sig.signer_name, "comment": sig.comment or ""}
-            for sig in approval.signatures
-        ]
-
-        # 建構通知訊息
-        message = NotificationMessage(
-            execution_status=execution_status,
-            action_title=approval.action[:100],
-            action_description=approval.description[:200] if approval.description else "",
-            approval_id=str(approval.id),
-            signers=signers,
-            required_signatures=approval.required_signatures,
-            affected_pods=approval.blast_radius.affected_pods if approval.blast_radius else 0,
-            estimated_downtime=approval.blast_radius.estimated_downtime if approval.blast_radius else "N/A",
-            related_services=approval.blast_radius.related_services if approval.blast_radius else [],
-            data_impact=approval.blast_radius.data_impact.value if approval.blast_radius else "none",
-            namespace=namespace,
-            operation_type=operation_type,
-            duration_ms=duration_ms,
-            error_message=error_message,
-            risk_level=approval.risk_level.value,
-            ai_provider=approval.requested_by,
-        )
-
-        # 發送通知
-        manager = get_notification_manager()
-        results = await manager.send_all(message)
-
-        for result in results:
-            logger.info(
-                "notification_result",
-                approval_id=str(approval.id),
-                provider=result.provider,
-                status=result.status.value,
-                message=result.message,
-            )
-
-    except Exception as e:
-        logger.exception(
-            "notification_failed",
-            approval_id=str(approval.id),
-            error=str(e),
-        )
-
-
 # =============================================================================
 # GET /api/v1/approvals/pending
 # =============================================================================
@@ -557,7 +354,8 @@ async def sign_approval(
             approval_id=str(approval_id),
         )
 
-        background_tasks.add_task(execute_approved_action, approval)
+        execution_svc = get_execution_service()
+        background_tasks.add_task(execution_svc.execute_approved_action, approval)
 
         # Phase 6.5: 更新關聯的 Incident 狀態為 RESOLVED
         # 🔴 關鍵: 這是審核後 Incident 狀態更新的核心邏輯
@@ -813,7 +611,8 @@ async def bulk_approve(
 
             # 如果觸發執行，加入背景任務
             if execution_triggered:
-                background_tasks.add_task(execute_approved_action, signed_approval)
+                bulk_execution_svc = get_execution_service()
+                background_tasks.add_task(bulk_execution_svc.execute_approved_action, signed_approval)
 
                 # 更新關聯的 Incident 狀態
                 incident_id = signed_approval.metadata.get("incident_id") if signed_approval.metadata else None
diff --git a/apps/api/src/services/approval_execution.py b/apps/api/src/services/approval_execution.py
new file mode 100644
index 00000000..56bbcdd8
--- /dev/null
+++ b/apps/api/src/services/approval_execution.py
@@ -0,0 +1,271 @@
+"""
+Approval Execution Service - Phase 16 R4.2 瘦身 Router 抽取
+============================================================
+
+從 approvals.py 抽取執行編排邏輯，整合:
+- OperationParser: 解析操作類型
+- K8s Executor: 執行 K8s 操作
+- ApprovalDBService: 更新狀態
+- TimelineService: 記錄事件
+- NotificationManager: 發送通知
+
+版本: v1.0
+建立: 2026-03-25 (台北時區)
+建立者: Claude Code (Phase 16 R4.2)
+"""
+
+import asyncio
+from typing import TYPE_CHECKING
+
+import structlog
+
+from src.core.config import settings
+from src.models.approval import ApprovalRequest
+from src.services.approval_db import get_approval_service, get_timeline_service
+from src.services.executor import get_executor
+from src.services.operation_parser import parse_operation_from_action
+
+if TYPE_CHECKING:
+    from src.services.notifications import ExecutionStatus
+
+logger = structlog.get_logger(__name__)
+
+
+class ApprovalExecutionService:
+    """
+    授權執行服務 - 編排整個執行流程
+
+    職責:
+    1. 解析操作類型
+    2. 呼叫 K8s Executor 執行
+    3. 更新資料庫狀態
+    4. 記錄 Timeline 事件
+    5. 發送通知
+    """
+
+    async def execute_approved_action(self, approval: ApprovalRequest) -> None:
+        """
+        背景執行已批准的操作
+
+        此函數由 BackgroundTasks 呼叫，不阻塞 API 回應
+        Phase 5: 執行後更新資料庫狀態
+        Phase 6: 執行後發送通知 (Post-Execution Hook)
+
+        Args:
+            approval: 已批准的授權請求
+        """
+        from src.services.notifications import ExecutionStatus
+
+        logger.info(
+            "background_execution_start",
+            approval_id=str(approval.id),
+            action=approval.action,
+        )
+
+        service = get_approval_service()
+        timeline = get_timeline_service()
+
+        # Parse operation details
+        parsed = parse_operation_from_action(approval.action)
+        operation_type = parsed.operation_type
+        resource_name = parsed.resource_name
+        namespace = parsed.namespace
+
+        if operation_type is None or resource_name is None:
+            logger.warning(
+                "background_execution_skip",
+                approval_id=str(approval.id),
+                reason="Could not parse operation type from action",
+                action=approval.action,
+            )
+            # Phase 5: 更新資料庫狀態
+            await service.update_execution_status(approval.id, success=False)
+            await timeline.add_event(
+                event_type="exec",
+                status="error",
+                title="執行失敗: 無法解析操作類型",
+                description=f"Action: {approval.action}",
+                actor="leWOOOgo",
+                actor_role="executor",
+                approval_id=str(approval.id),
+            )
+
+            # Phase 6: 發送失敗通知 (fire-and-forget)
+            asyncio.create_task(
+                self._send_execution_notification(
+                    approval=approval,
+                    execution_status=ExecutionStatus.FAILED,
+                    operation_type="unknown",
+                    namespace=namespace,
+                    error_message="Could not parse operation type",
+                )
+            )
+            return
+
+        # Execute with audit
+        executor = get_executor()
+        result = await executor.execute_with_audit(
+            approval=approval,
+            operation_type=operation_type,
+            resource_name=resource_name,
+            namespace=namespace,
+        )
+
+        # Phase 5: 更新資料庫狀態
+        await service.update_execution_status(approval.id, success=result.success)
+
+        # Update approval status based on result
+        if result.success:
+            logger.info(
+                "background_execution_success",
+                approval_id=str(approval.id),
+                operation=operation_type.value,
+                target=resource_name,
+                namespace=namespace,
+                duration_ms=result.duration_ms,
+            )
+            await timeline.add_event(
+                event_type="exec",
+                status="success",
+                title=f"✅ K8s 執行成功: {operation_type.value}",
+                description=f"Target: {resource_name} @ {namespace} ({result.duration_ms}ms)",
+                actor="leWOOOgo",
+                actor_role="executor",
+                approval_id=str(approval.id),
+            )
+
+            # Phase 6: 發送成功通知 (fire-and-forget)
+            asyncio.create_task(
+                self._send_execution_notification(
+                    approval=approval,
+                    execution_status=ExecutionStatus.SUCCESS,
+                    operation_type=operation_type.value,
+                    namespace=namespace,
+                    duration_ms=result.duration_ms,
+                )
+            )
+        else:
+            logger.error(
+                "background_execution_failed",
+                approval_id=str(approval.id),
+                operation=operation_type.value,
+                target=resource_name,
+                namespace=namespace,
+                error=result.error,
+            )
+            await timeline.add_event(
+                event_type="exec",
+                status="error",
+                title=f"❌ K8s 執行失敗: {operation_type.value}",
+                description=f"Error: {result.error}",
+                actor="leWOOOgo",
+                actor_role="executor",
+                approval_id=str(approval.id),
+            )
+
+            # Phase 6: 發送失敗通知 (fire-and-forget, 包含 Dry-Run 攔截)
+            exec_status = (
+                ExecutionStatus.DRY_RUN_BLOCKED
+                if "not found" in (result.error or "")
+                else ExecutionStatus.FAILED
+            )
+            asyncio.create_task(
+                self._send_execution_notification(
+                    approval=approval,
+                    execution_status=exec_status,
+                    operation_type=operation_type.value,
+                    namespace=namespace,
+                    error_message=result.error,
+                    duration_ms=result.duration_ms,
+                )
+            )
+
+    async def _send_execution_notification(
+        self,
+        approval: ApprovalRequest,
+        execution_status: "ExecutionStatus",
+        operation_type: str,
+        namespace: str,
+        duration_ms: int | None = None,
+        error_message: str | None = None,
+    ) -> None:
+        """
+        Phase 6: 發送執行通知 (Post-Execution Hook)
+
+        將執行結果發送至所有已配置的通知頻道 (Discord, Slack, etc.)
+        """
+        from src.services.notifications import (
+            NotificationMessage,
+            get_notification_manager,
+        )
+
+        if not settings.NOTIFICATION_ENABLED:
+            logger.info("notification_disabled", approval_id=str(approval.id))
+            return
+
+        try:
+            # 建構簽核者列表
+            signers = [
+                {"name": sig.signer_name, "comment": sig.comment or ""}
+                for sig in approval.signatures
+            ]
+
+            # 建構通知訊息
+            message = NotificationMessage(
+                execution_status=execution_status,
+                action_title=approval.action[:100],
+                action_description=approval.description[:200] if approval.description else "",
+                approval_id=str(approval.id),
+                signers=signers,
+                required_signatures=approval.required_signatures,
+                affected_pods=approval.blast_radius.affected_pods if approval.blast_radius else 0,
+                estimated_downtime=approval.blast_radius.estimated_downtime if approval.blast_radius else "N/A",
+                related_services=approval.blast_radius.related_services if approval.blast_radius else [],
+                data_impact=approval.blast_radius.data_impact.value if approval.blast_radius else "none",
+                namespace=namespace,
+                operation_type=operation_type,
+                duration_ms=duration_ms,
+                error_message=error_message,
+                risk_level=approval.risk_level.value,
+                ai_provider=approval.requested_by,
+            )
+
+            # 發送通知
+            manager = get_notification_manager()
+            results = await manager.send_all(message)
+
+            for result in results:
+                logger.info(
+                    "notification_result",
+                    approval_id=str(approval.id),
+                    provider=result.provider,
+                    status=result.status.value,
+                    message=result.message,
+                )
+
+        except Exception as e:
+            logger.exception(
+                "notification_failed",
+                approval_id=str(approval.id),
+                error=str(e),
+            )
+
+
+# =============================================================================
+# Singleton Instance
+# =============================================================================
+
+_execution_service: ApprovalExecutionService | None = None
+
+
+def get_execution_service() -> ApprovalExecutionService:
+    """
+    取得 ApprovalExecutionService 單例
+
+    Returns:
+        ApprovalExecutionService: 執行服務實例
+    """
+    global _execution_service
+    if _execution_service is None:
+        _execution_service = ApprovalExecutionService()
+    return _execution_service