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/api/models/document.models.ts

@@ -0,0 +1,54 @@
+/**
+ * Document API Models
+ * Models for document management
+ */
+
+export type DocumentType =
+  | 'FIRE_SAFETY_CERTIFICATE'
+  | 'BUILDING_PLAN'
+  | 'PROPERTY_OWNERSHIP'
+  | 'INSPECTION_REPORT'
+  | 'POLLUTION_CERTIFICATE'
+  | 'ELECTRICAL_SAFETY_CERTIFICATE'
+  | 'STRUCTURAL_STABILITY_CERTIFICATE'
+  | 'IDENTITY_PROOF'
+  | 'ADDRESS_PROOF'
+  | 'OTHER';
+
+export interface UploadDocumentDto {
+  docType: DocumentType;
+  description?: string;
+  file?: File;
+}
+
+export interface DocumentResponseDto {
+  id: string;
+  requestId: string;
+  docType: string;
+  originalFilename: string;
+  currentVersion: number;
+  currentHash: string;
+  minioBucket: string;
+  isActive: boolean;
+  createdAt: string;
+  updatedAt: string;
+}
+
+export interface DocumentVersionResponseDto {
+  id: string;
+  documentId: string;
+  version: number;
+  hash: string;
+  minioPath: string;
+  fileSize: string;
+  mimeType: string;
+  uploadedBy: string;
+  blockchainTxHash?: string;
+  createdAt: string;
+}
+
+export interface DownloadUrlResponseDto {
+  url: string;
+  expiresAt: string;
+  expiresIn: number;
+}