fix(preferences): ajusted schema so is_dark_mode accepts null

prisma/schema.prisma

@@ -348,7 +348,7 @@ model Preferences {
   user_id String @unique @db.Uuid
 
   notifications              Boolean @default(true)
-  is_dark_mode               Boolean @default(false)
+  is_dark_mode               Boolean? @default(false)
   display_language           String  @default("fr-FR") //'fr-FR' | 'en-CA';
   is_lefty_mode              Boolean @default(false)
   is_employee_list_grid      Boolean @default(true)

src/identity-and-account/preferences/services/preferences.service.ts

@@ -50,7 +50,7 @@ export class PreferencesService {
                 where: { user_id: user_id.data },
                 data: {
                     notifications: dto.notifications,
-                    is_dark_mode: dto.is_dark_mode ?? undefined,
+                    is_dark_mode: dto.is_dark_mode,
                     display_language: dto.display_language,
                     is_lefty_mode: dto.is_lefty_mode,
                     is_employee_list_grid: dto.is_employee_list_grid,

src/modules/exports/dtos/export-csv-options.dto.ts

@@ -1,7 +1,7 @@
 import { Transform } from "class-transformer";
 import { IsBoolean, IsInt, IsOptional, Max, Min } from "class-validator";
 
-function toBoolean(v: any) {
+const toBoolean = (v: any) => {
     if(typeof v === 'boolean') return v;
     if(typeof v === 'string') return ['true', '1', 'on','yes'].includes(v.toLowerCase());
     return false;