feat: add schedule preview functionality for production plans

- Implemented previewSchedule and previewSemiSchedule functions in the production controller to allow users to preview schedule changes without making actual database modifications.
- Added corresponding routes for schedule preview in productionRoutes.
- Enhanced productionPlanService with logic to generate schedule previews based on provided items and plan IDs.
- Introduced SchedulePreviewDialog component to display the preview results in the frontend, including summary and detailed views of planned schedules.

These updates improve the user experience by providing a way to visualize scheduling changes before applying them, ensuring better planning and decision-making.

Made-with: Cursor

backend-node/src/controllers/productionController.ts

@@ -95,6 +95,25 @@ export async function deletePlan(req: AuthenticatedRequest, res: Response) {
   }
 }
 
+// ─── 자동 스케줄 미리보기 (실제 INSERT 없이 예상 결과 반환) ───
+
+export async function previewSchedule(req: AuthenticatedRequest, res: Response) {
+  try {
+    const companyCode = req.user!.companyCode;
+    const { items, options } = req.body;
+
+    if (!items || !Array.isArray(items) || items.length === 0) {
+      return res.status(400).json({ success: false, message: "품목 정보가 필요합니다" });
+    }
+
+    const data = await productionService.previewSchedule(companyCode, items, options || {});
+    return res.json({ success: true, data });
+  } catch (error: any) {
+    logger.error("자동 스케줄 미리보기 실패", { error: error.message });
+    return res.status(500).json({ success: false, message: error.message });
+  }
+}
+
 // ─── 자동 스케줄 생성 ───
 
 export async function generateSchedule(req: AuthenticatedRequest, res: Response) {
@@ -141,6 +160,29 @@ export async function mergeSchedules(req: AuthenticatedRequest, res: Response) {
   }
 }
 
+// ─── 반제품 계획 미리보기 (실제 변경 없이 예상 결과) ───
+
+export async function previewSemiSchedule(req: AuthenticatedRequest, res: Response) {
+  try {
+    const companyCode = req.user!.companyCode;
+    const { plan_ids, options } = req.body;
+
+    if (!plan_ids || !Array.isArray(plan_ids) || plan_ids.length === 0) {
+      return res.status(400).json({ success: false, message: "완제품 계획을 선택해주세요" });
+    }
+
+    const data = await productionService.previewSemiSchedule(
+      companyCode,
+      plan_ids,
+      options || {}
+    );
+    return res.json({ success: true, data });
+  } catch (error: any) {
+    logger.error("반제품 계획 미리보기 실패", { error: error.message });
+    return res.status(500).json({ success: false, message: error.message });
+  }
+}
+
 // ─── 반제품 계획 자동 생성 ───
 
 export async function generateSemiSchedule(req: AuthenticatedRequest, res: Response) {