feat(tenders): add Tender Management module (SRS, backend, frontend)

- SRS document: docs/SRS_TENDER_MANAGEMENT.md
- Prisma: Tender, TenderDirective models; Deal.sourceTenderId; Attachment.tenderId/tenderDirectiveId
- Backend: tenders module (CRUD, duplicate check, directives, notifications, file upload, convert-to-deal)
- Frontend: tenders list, detail, create/edit forms, directives, convert to deal, i18n (en/ar), dashboard card
- Seed: tenders permissions for admin and sales positions
- Auth: admin.service findFirst for email check (Prisma compatibility)

Made-with: Cursor

backend/prisma/seed.js

@@ -30,7 +30,7 @@ async function main() {
     },
   });
 
-  const modules = ['contacts', 'crm', 'inventory', 'projects', 'hr', 'marketing', 'admin'];
+  const modules = ['contacts', 'crm', 'tenders', 'inventory', 'projects', 'hr', 'marketing', 'admin'];
   for (const module of modules) {
     await prisma.positionPermission.create({
       data: {
@@ -67,6 +67,8 @@ async function main() {
     data: [
       { positionId: salesRepPosition.id, module: 'contacts', resource: '*', actions: ['read', 'create', 'update'] },
       { positionId: salesRepPosition.id, module: 'crm', resource: 'deals', actions: ['read', 'create', 'update'] },
+      { positionId: salesRepPosition.id, module: 'tenders', resource: 'tenders', actions: ['read', 'create', 'update'] },
+      { positionId: salesRepPosition.id, module: 'tenders', resource: 'directives', actions: ['read', 'create', 'update'] },
     ],
   });