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

backend/src/blockchain/blockchain.module.ts

@@ -0,0 +1,8 @@
+import { Module } from '@nestjs/common';
+import { BlockchainService } from './blockchain.service';
+
+@Module({
+  providers: [BlockchainService],
+  exports: [BlockchainService],
+})
+export class BlockchainModule {}

backend/src/blockchain/blockchain.service.ts

@@ -0,0 +1,67 @@
+import { Injectable, Logger, Inject } from '@nestjs/common';
+import { ConfigService } from '@nestjs/config';
+import { ethers } from 'ethers';
+
+export interface BlockchainConfig {
+  rpcUrl: string;
+  chainId: number;
+  gasPrice: string;
+  gasLimit: string;
+  contractAddress: string;
+  privateKey: string;
+  networkName: string;
+}
+
+@Injectable()
+export class BlockchainService {
+  private readonly logger = new Logger(BlockchainService.name);
+  private provider: ethers.JsonRpcProvider | null = null;
+  private signer: ethers.Wallet | null = null;
+
+  constructor(@Inject(ConfigService) private configService: ConfigService) {}
+
+  async initialize(): Promise<void> {
+    try {
+      const config = this.configService.get<BlockchainConfig>('blockchain');
+
+      if (!config) {
+        throw new Error('Blockchain configuration not found');
+      }
+
+      this.provider = new ethers.JsonRpcProvider(config.rpcUrl);
+      this.signer = new ethers.Wallet(config.privateKey, this.provider);
+
+      const network = await this.provider.getNetwork();
+      this.logger.log(
+        `Connected to blockchain network: ${network.name} (Chain ID: ${network.chainId})`,
+      );
+    } catch (error) {
+      this.logger.error('Failed to initialize blockchain service', error);
+      throw error;
+    }
+  }
+
+  getProvider(): ethers.JsonRpcProvider {
+    if (!this.provider) {
+      throw new Error('Blockchain provider not initialized');
+    }
+    return this.provider;
+  }
+
+  getSigner(): ethers.Wallet {
+    if (!this.signer) {
+      throw new Error('Blockchain signer not initialized');
+    }
+    return this.signer;
+  }
+
+  async getBalance(address: string): Promise<string> {
+    const balance = await this.provider!.getBalance(address);
+    return ethers.formatEther(balance);
+  }
+
+  async getTransactionStatus(transactionHash: string): Promise<string | null> {
+    const receipt = await this.provider!.getTransactionReceipt(transactionHash);
+    return receipt?.status === 1 ? 'success' : 'failed';
+  }
+}