feat(activities): split customer column, wider search, custom activity types with type-specific fields

- Table: separate assignee and customer columns; search by assignee and activity type
- ActivityTypeDef model with per-type field definitions (text, select, checklist, participants, ...)
- Default types incl. meeting subject/participants and task checklist; admins manage types
- Participants see activities in their lists and get notified

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

apps/api/src/common/record-scope.ts

@@ -124,6 +124,21 @@ export function assigneeWhere(
   };
 }
 
+/** دسترسی به فعالیت: مسئولان یا شرکت‌کنندگان (فیلد شرکت‌کنندگان) در محدوده دید */
+export function activityAccessWhere(
+  actor: ScopedActor,
+): Prisma.ActivityWhereInput {
+  const ids = scopedOwnerIds(actor, 'activities');
+  if (!ids) return {};
+  return {
+    OR: [
+      { assigneeId: { in: ids } },
+      { assignees: { some: { id: { in: ids } } } },
+      { participantIds: { hasSome: ids } },
+    ],
+  };
+}
+
 /** یادداشت: نویسنده یا پرونده‌های تحت مالکیت در محدوده دید + محرمانگی شخصی */
 export function noteAccessWhere(
   actor: ScopedActor,