fix(leads): keep a future follow-up as an activity on the lead

A scheduled follow-up only stored a date, and activities opened from a lead were not linked back, so they disappeared from the lead.

Co-authored-by: Cursor <cursoragent@cursor.com>

apps/api/src/leads/leads.service.ts

@@ -810,14 +810,14 @@ export class LeadsService {
       ? `تماس ثبت شد — ${dto.outcome}`
       : 'تماس ثبت شد';
     await this.addEvent(actor, id, 'call', title, dto.body ?? null);
+    const followAt = this.parseFollowUpAt(dto.nextFollowUpAt);
+    if (followAt) {
+      await this.createLeadFollowUpActivity(actor, before, followAt, dto.body);
+    }
     const data: Prisma.LeadUpdateInput = {
       lastContactAt: new Date(),
       ...(dto.nextFollowUpAt !== undefined
-        ? {
-            nextFollowUpAt: dto.nextFollowUpAt
-              ? new Date(dto.nextFollowUpAt)
-              : null,
-          }
+        ? { nextFollowUpAt: followAt }
         : {}),
     };
     if (dto.stageId) data.stage = { connect: { id: dto.stageId } };
@@ -856,8 +856,10 @@ export class LeadsService {
     nextFollowUpAt: string,
     body?: string,
   ): Promise<LeadDto> {
-    await this.findAccessible(actor, id);
-    const at = new Date(nextFollowUpAt);
+    const lead = await this.findAccessible(actor, id);
+    const at = this.parseFollowUpAt(nextFollowUpAt);
+    if (!at) throw new BadRequestException('زمان پیگیری نامعتبر است');
+    await this.createLeadFollowUpActivity(actor, lead, at, body);
     await this.addEvent(
       actor,
       id,
@@ -878,6 +880,39 @@ export class LeadsService {
     return this.toDto(row);
   }
 
+  /** پیگیری آینده باید خودش یک فعالیت باز و متصل به لید باشد، نه فقط یک تاریخ. */
+  private parseFollowUpAt(value?: string | null): Date | null {
+    if (!value) return null;
+    const at = new Date(value);
+    if (Number.isNaN(at.getTime())) {
+      throw new BadRequestException('زمان پیگیری نامعتبر است');
+    }
+    return at;
+  }
+
+  private async createLeadFollowUpActivity(
+    actor: Actor,
+    lead: { id: string; title: string; assigneeId: string | null },
+    dueAt: Date,
+    body?: string | null,
+  ) {
+    const allowOthers = await actorCanAssignToOthers(this.prisma, actor, 'activities');
+    const assigneeId = allowOthers && lead.assigneeId ? lead.assigneeId : actor.userId;
+    await this.prisma.activity.create({
+      data: {
+        organizationId: actor.organizationId,
+        type: 'task',
+        title: `پیگیری: ${lead.title}`.slice(0, 200),
+        description: body?.trim() || null,
+        dueAt,
+        leadId: lead.id,
+        assigneeId,
+        assignees: { connect: [{ id: assigneeId }] },
+        createdById: actor.userId,
+      },
+    });
+  }
+
   async archive(actor: Actor, ids: string[]): Promise<number> {
     if (!elevated(actor.role) && ids.length > 1) {
       throw new BadRequestException('حذف گروهی فقط برای مدیر');