feat: Runtime configuration and Docker deployment improvements

Frontend:
- Add runtime configuration service for deployment-time API URL injection
- Create docker-entrypoint.sh to generate config.json from environment variables
- Update ApiService, ApprovalService, and DocumentViewer to use RuntimeConfigService
- Add APP_INITIALIZER to load runtime config before app starts

Backend:
- Fix init-blockchain.js to properly quote mnemonic phrases in .env file
- Improve docker-entrypoint.sh with health checks and better error handling

Docker:
- Add API_BASE_URL environment variable to frontend container
- Update docker-compose.yml with clear documentation for remote deployment
- Reorganize .env.example with clear categories (REQUIRED FOR REMOTE, PRODUCTION, AUTO-GENERATED)

Workflow fixes:
- Fix DepartmentApproval interface to match backend schema
- Fix stage transformation for 0-indexed stageOrder
- Fix workflow list to show correct stage count from definition.stages

Cleanup:
- Move development artifacts to .trash directory
- Remove root-level package.json (was only for utility scripts)
- Add .trash/ to .gitignore

backend/src/modules/documents/dto/document-response.dto.ts

@@ -38,6 +38,18 @@ export class DocumentResponseDto {
   })
   fileHash?: string;
 
+  @ApiProperty({
+    description: 'File size in bytes',
+    required: false,
+  })
+  fileSize?: number;
+
+  @ApiProperty({
+    description: 'MIME type of the file',
+    required: false,
+  })
+  mimeType?: string;
+
   @ApiProperty({
     description: 'MinIO bucket name',
   })