add file viewer functionality across various components

- Implemented a shared file viewer modal using `useFileViewer` hook to allow inline viewing of documents (images, PDFs, videos, etc.) across the application.
- Updated `ContractClearanceReviewSection`, `ContractRequestDetailPage`, `ContractViewPage`, and booking-related components to utilize the new file viewer for document previews.
- Added "Approve all" button in `ContractClearanceReviewSection` to bulk approve documents.
- Enhanced document action buttons to include view and download options based on file type.
- Introduced `isViewable` utility to determine if a file can be previewed inline.
- Created `FileViewer` component to handle rendering of various file types and added appropriate fallback for unsupported formats.

apps/edr-freight-api/src/modules/contracts/contracts.controller.ts

@@ -42,6 +42,7 @@ import { ContractTransitionService } from './contract-transition.service';
 import { ContractClearanceService } from './contract-clearance.service';
 import { ContractBookingService } from './contract-booking.service';
 import { ClearanceMilestoneService } from './clearance-milestone.service';
+import { SignaturesService } from '../signatures/signatures.service';
 import { CreateContractDto } from './dto/create-contract.dto';
 import { UpdateContractDto } from './dto/update-contract.dto';
 import { FilterContractDto } from './dto/filter-contract.dto';
@@ -68,6 +69,7 @@ export class ContractsController {
     private readonly clearanceService: ContractClearanceService,
     private readonly contractBookingService: ContractBookingService,
     private readonly milestoneService: ClearanceMilestoneService,
+    private readonly signaturesService: SignaturesService,
   ) {}
 
   @Post()
@@ -313,6 +315,12 @@ export class ContractsController {
     }
     const { view, html, signatures } =
       await this.transitionService.getContractDocumentView(id);
+    // The signer's reusable saved signature (if any) so the sign UI can offer
+    // "Approve & sign" with the stored image instead of forcing a fresh draw.
+    const signerId = resolveAuthUserId(user);
+    const savedSignature = signerId
+      ? await this.signaturesService.getForUser(signerId)
+      : null;
     return {
       contractId: view.bookingId,
       reference: view.reference,
@@ -325,6 +333,7 @@ export class ContractsController {
       canSignStaff: view.canSignStaff,
       hasContractDocument: view.hasContractDocument,
       signatures,
+      savedSignature,
     };
   }