feat: Goa GEL Blockchain e-Licensing Platform - Full Stack Implementation

Complete implementation of the Goa Government e-Licensing platform with:

Backend:
- NestJS API with JWT authentication
- PostgreSQL database with Knex ORM
- Redis caching and session management
- MinIO document storage
- Hyperledger Besu blockchain integration
- Multi-department workflow system
- Comprehensive API tests (266/282 passing)

Frontend:
- Angular 21 with standalone components
- Angular Material + TailwindCSS UI
- Visual workflow builder
- Document upload with progress tracking
- Blockchain explorer integration
- Role-based dashboards (Admin, Department, Citizen)
- E2E tests with Playwright (37 tests)

Infrastructure:
- Docker Compose orchestration
- Blockscout blockchain explorer
- Development and production configurations

frontend/src/app/features/documents/services/document.service.ts

@@ -0,0 +1,95 @@
+import { Injectable, inject } from '@angular/core';
+import { Observable } from 'rxjs';
+import { ApiService, UploadProgress } from '../../../core/services/api.service';
+import {
+  DocumentResponseDto,
+  DocumentVersionResponseDto,
+  DownloadUrlResponseDto,
+  DocumentType,
+} from '../../../api/models';
+
+@Injectable({
+  providedIn: 'root',
+})
+export class DocumentService {
+  private readonly api = inject(ApiService);
+
+  getDocuments(requestId: string): Observable<DocumentResponseDto[]> {
+    return this.api.get<DocumentResponseDto[]>(`/requests/${requestId}/documents`);
+  }
+
+  getDocument(requestId: string, documentId: string): Observable<DocumentResponseDto> {
+    return this.api.get<DocumentResponseDto>(`/requests/${requestId}/documents/${documentId}`);
+  }
+
+  getDocumentVersions(
+    requestId: string,
+    documentId: string
+  ): Observable<DocumentVersionResponseDto[]> {
+    return this.api.get<DocumentVersionResponseDto[]>(
+      `/requests/${requestId}/documents/${documentId}/versions`
+    );
+  }
+
+  uploadDocument(
+    requestId: string,
+    file: File,
+    docType: DocumentType,
+    description?: string
+  ): Observable<DocumentResponseDto> {
+    const formData = new FormData();
+    formData.append('file', file);
+    formData.append('docType', docType);
+    if (description) {
+      formData.append('description', description);
+    }
+    return this.api.upload<DocumentResponseDto>(`/requests/${requestId}/documents`, formData);
+  }
+
+  /**
+   * Upload document with progress tracking
+   */
+  uploadDocumentWithProgress(
+    requestId: string,
+    file: File,
+    docType: DocumentType,
+    description?: string
+  ): Observable<UploadProgress<DocumentResponseDto>> {
+    const formData = new FormData();
+    formData.append('file', file);
+    formData.append('docType', docType);
+    if (description) {
+      formData.append('description', description);
+    }
+    return this.api.uploadWithProgress<DocumentResponseDto>(`/requests/${requestId}/documents`, formData);
+  }
+
+  updateDocument(
+    requestId: string,
+    documentId: string,
+    file: File
+  ): Observable<DocumentResponseDto> {
+    const formData = new FormData();
+    formData.append('file', file);
+    return this.api.upload<DocumentResponseDto>(
+      `/requests/${requestId}/documents/${documentId}`,
+      formData
+    );
+  }
+
+  deleteDocument(requestId: string, documentId: string): Observable<void> {
+    return this.api.delete<void>(`/requests/${requestId}/documents/${documentId}`);
+  }
+
+  getDownloadUrl(requestId: string, documentId: string): Observable<DownloadUrlResponseDto> {
+    return this.api.get<DownloadUrlResponseDto>(
+      `/requests/${requestId}/documents/${documentId}/download`
+    );
+  }
+
+  verifyDocument(requestId: string, documentId: string): Observable<{ verified: boolean }> {
+    return this.api.get<{ verified: boolean }>(
+      `/requests/${requestId}/documents/${documentId}/verify`
+    );
+  }
+}