diff --git a/.superpowers/sdd/task-5-report.md b/.superpowers/sdd/task-5-report.md
new file mode 100644
index 0000000..180e3f6
--- /dev/null
+++ b/.superpowers/sdd/task-5-report.md
@@ -0,0 +1,17 @@
+# Task 5 report
+Status: DONE
+- shared build: OK
+- pipeline-merge.test.ts: 5/5 pass
+- api typecheck: OK
+- vue-tsc: see VUE_EXIT in controller log
+- graphify: attempted (may crash)
+No commit required for verification-only task.
+
+## Follow-up fix: final review important findings
+Status: DONE
+- I-1: Added in-transaction unmoved-deal count guard before deleting the source pipeline.
+- I-3: Added 30000ms timeout to the interactive merge transaction.
+- M-1: Added `@IsIn(['retarget_all'])` validation to `MergePipelineDto.leadFormMode`.
+- graphify update: OK
+- `cd apps/api; npx tsx --test test/pipeline-merge.test.ts`: OK, 5/5 pass
+- `npm run typecheck -w @mento/api`: OK
diff --git a/apps/api/src/pipelines/dto.ts b/apps/api/src/pipelines/dto.ts
index 5b208cb..9ef327a 100644
--- a/apps/api/src/pipelines/dto.ts
+++ b/apps/api/src/pipelines/dto.ts
@@ -4,6 +4,7 @@ import {
   IsArray,
   IsBoolean,
   IsDateString,
+  IsIn,
   IsInt,
   IsNumber,
   IsObject,
@@ -362,5 +363,6 @@ export class MergePipelineDto {
 
   @IsOptional()
   @IsString()
+  @IsIn(['retarget_all'])
   leadFormMode?: 'retarget_all';
 }
diff --git a/apps/api/src/pipelines/pipelines.service.ts b/apps/api/src/pipelines/pipelines.service.ts
index 82aed65..572b4fc 100644
--- a/apps/api/src/pipelines/pipelines.service.ts
+++ b/apps/api/src/pipelines/pipelines.service.ts
@@ -416,87 +416,101 @@ export class PipelinesService {
       );
     }
 
-    const targetStagesById = new Map(target.stages.map((stage) => [stage.id, stage]));
+    const targetStagesById = new Map(
+      target.stages.map((stage) => [stage.id, stage]),
+    );
     let movedDeals = 0;
     let retargetedLeadForms = 0;
 
-    await this.prisma.$transaction(async (tx) => {
-      const closedAt = new Date();
-      for (const sourceStage of source.stages) {
-        const targetStageId = dto.stageMap[sourceStage.id];
-        const targetStage = targetStagesById.get(targetStageId);
-        if (!targetStage) {
-          throw new BadRequestException('نگاشت ستون‌ها نامعتبر است');
-        }
-        const status = dealStatusForStage(targetStage);
+    await this.prisma.$transaction(
+      async (tx) => {
+        const closedAt = new Date();
+        for (const sourceStage of source.stages) {
+          const targetStageId = dto.stageMap[sourceStage.id];
+          const targetStage = targetStagesById.get(targetStageId);
+          if (!targetStage) {
+            throw new BadRequestException('نگاشت ستون‌ها نامعتبر است');
+          }
+          const status = dealStatusForStage(targetStage);
 
-        if (status === 'open') {
-          const result = await tx.deal.updateMany({
+          if (status === 'open') {
+            const result = await tx.deal.updateMany({
+              where: {
+                organizationId,
+                pipelineId: source.id,
+                stageId: sourceStage.id,
+              },
+              data: {
+                pipelineId: target.id,
+                stageId: targetStage.id,
+                status,
+                closedAt: null,
+              },
+            });
+            movedDeals += result.count;
+            continue;
+          }
+
+          const opened = await tx.deal.updateMany({
             where: {
               organizationId,
               pipelineId: source.id,
               stageId: sourceStage.id,
+              status: 'open',
             },
             data: {
               pipelineId: target.id,
               stageId: targetStage.id,
               status,
-              closedAt: null,
+              closedAt,
             },
           });
-          movedDeals += result.count;
-          continue;
+          const alreadyClosed = await tx.deal.updateMany({
+            where: {
+              organizationId,
+              pipelineId: source.id,
+              stageId: sourceStage.id,
+              status: { not: 'open' },
+            },
+            data: {
+              pipelineId: target.id,
+              stageId: targetStage.id,
+              status,
+            },
+          });
+          movedDeals += opened.count + alreadyClosed.count;
         }
 
-        const opened = await tx.deal.updateMany({
-          where: {
-            organizationId,
-            pipelineId: source.id,
-            stageId: sourceStage.id,
-            status: 'open',
-          },
-          data: {
-            pipelineId: target.id,
-            stageId: targetStage.id,
-            status,
-            closedAt,
-          },
+        const leadForms = await tx.leadForm.updateMany({
+          where: { organizationId, pipelineId: source.id },
+          data: { pipelineId: target.id },
         });
-        const alreadyClosed = await tx.deal.updateMany({
-          where: {
-            organizationId,
-            pipelineId: source.id,
-            stageId: sourceStage.id,
-            status: { not: 'open' },
-          },
-          data: {
-            pipelineId: target.id,
-            stageId: targetStage.id,
-            status,
-          },
-        });
-        movedDeals += opened.count + alreadyClosed.count;
-      }
+        retargetedLeadForms = leadForms.count;
 
-      const leadForms = await tx.leadForm.updateMany({
-        where: { organizationId, pipelineId: source.id },
-        data: { pipelineId: target.id },
-      });
-      retargetedLeadForms = leadForms.count;
+        if (source.isDefault) {
+          await tx.pipeline.updateMany({
+            where: { organizationId, isDefault: true },
+            data: { isDefault: false },
+          });
+          await tx.pipeline.update({
+            where: { id: target.id },
+            data: { isDefault: true },
+          });
+        }
 
-      if (source.isDefault) {
-        await tx.pipeline.updateMany({
-          where: { organizationId, isDefault: true },
-          data: { isDefault: false },
+        const remaining = await tx.deal.count({
+          where: { organizationId, pipelineId: source.id },
         });
-        await tx.pipeline.update({
-          where: { id: target.id },
-          data: { isDefault: true },
-        });
-      }
+        if (remaining > 0) {
+          throw new BadRequestException(
+            'برخی معامله‌ها منتقل نشدند؛ ادغام لغو شد.',
+          );
+        }
 
-      await tx.pipeline.delete({ where: { id: source.id } });
-    });
+        await tx.pipeline.delete({ where: { id: source.id } });
+      },
+      { timeout: 30000 },
+    );
 
     return {
       ok: true,