chore: add contract verification notes

.env.sample

@@ -1,2 +1,3 @@
 RPC_URL="https://mainnet.infura.io/v3/some-key"
 PRIVATE_KEY="super-secret-key"
+ETHERSCAN_API_KEY="etherscan-api-key"

README.md

@@ -16,11 +16,11 @@ Test: `npx hardhat test`
 
 ### Mainnet
 
-First configure the .env file with valid RPC_URL and PRIVATE_KEY values.
+First configure the .env file with valid `RPC_URL`, `PRIVATE_KEY` and `ETHERSCAN_API_KEY` values.
 
 Visualize the deployment plan: `npx hardhat ignition visualize ignition/modules/StakingRewards.ts --network mainnet`
 
-Deploy the contract: `npx hardhat ignition deploy ignition/modules/StakingRewards.ts --network mainnet`
+Deploy and verify the contract: `npx hardhat ignition deploy ignition/modules/StakingRewards.ts --network mainnet --verify`
 
 ### Local
 

hardhat.config.ts

@@ -29,6 +29,18 @@ const config: HardhatUserConfig = {
       },
     ],
   },
+  // Etherscan configuration for mainnet deployment verification
+  // Optional so we can still test locally without setting up etherscan
+  ...(process.env.ETHERSCAN_API_KEY
+    ? {
+      etherscan: {
+        apiKey: process.env.ETHERSCAN_API_KEY,
+      },
+    }
+    : {}),
+  sourcify: {
+    enabled: true,
+  },
 };
 
 export default config;