feat: add implementation deployment scripts and update documentation

- Introduced new scripts for deploying the DonationHandler implementation on both mainnet and sepolia in package.json.
- Expanded PRODUCTION_UPGRADE.md with instructions for deploying the implementation without ProxyAdmin access, including verification steps and handoff to the proxy owner.

Author: ae2079

PRODUCTION_UPGRADE.md

@@ -21,6 +21,39 @@ Based on your deployments:
 - [ ] Gas costs acceptable (~1.5M gas per network)
 - [ ] Have sufficient ETH/native tokens on all networks
 
+## 🔄 Alternative: Deploy implementation only (not the ProxyAdmin owner)
+
+If you don't have access to the ProxyAdmin owner key, you can still deploy and verify the new implementation. The proxy owner then performs the upgrade on their side.
+
+### 1. Deploy and verify the implementation
+
+```bash
+source .env
+yarn deploy:implementation:mainnet
+# or for testnet first: yarn deploy:implementation:sepolia
+```
+
+The script will output the new implementation address. Save it (e.g. `export NEW_IMPLEMENTATION_ADDRESS=0x...`).
+
+### 2. Hand off to the proxy owner
+
+Send the **implementation address** to the ProxyAdmin owner. They should run:
+
+```solidity
+proxyAdmin.upgrade(proxy, NEW_IMPLEMENTATION_ADDRESS);
+```
+
+Or via `cast`:
+
+```bash
+cast send $PROXY_ADMIN_ADDRESS "upgrade(address,address)" $PROXY_ADDRESS $NEW_IMPLEMENTATION_ADDRESS \
+  --rpc-url $MAINNET_RPC --private-key $OWNER_PRIVATE_KEY
+```
+
+No need for you to have proxy or ProxyAdmin addresses in `.env` for this flow; only `PRIVATE_KEY` and RPC URL are required to deploy and verify the implementation.
+
+---
+
 ## 🔍 Step 1: Find Your Proxy Addresses
 
 Your proxy addresses are in the broadcast folder. Let's extract them:

package.json

@@ -19,6 +19,8 @@
     "upgrade:mainnet": "bash -c 'source .env && forge script script/UpgradeDonationHandler.s.sol:UpgradeDonationHandler --rpc-url $MAINNET_RPC --broadcast --verify -vvvv'",
     "upgrade:mainnet:simulate": "bash -c 'source .env && forge script script/UpgradeDonationHandler.s.sol:UpgradeDonationHandler --fork-url $MAINNET_RPC -vvvv'",
     "upgrade:sepolia": "bash -c 'source .env && forge script script/UpgradeDonationHandler.s.sol:UpgradeDonationHandler --rpc-url $SEPOLIA_RPC --broadcast --verify -vvvv'",
+    "deploy:implementation:mainnet": "bash -c 'source .env && forge script script/DeployDonationHandlerImplementation.s.sol:DeployDonationHandlerImplementation --rpc-url $MAINNET_RPC --broadcast --verify -vvvv'",
+    "deploy:implementation:sepolia": "bash -c 'source .env && forge script script/DeployDonationHandlerImplementation.s.sol:DeployDonationHandlerImplementation --rpc-url $SEPOLIA_RPC --broadcast --verify -vvvv'",
     "lint:check": "yarn lint:sol && forge fmt --check",
     "lint:fix": "sort-package-json && forge fmt && yarn lint:sol --fix",
     "lint:natspec": "npx @defi-wonderland/natspec-smells --config natspec-smells.config.js",

script/DeployDonationHandlerImplementation.s.sol

@@ -0,0 +1,30 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.22;
+
+/// @notice Deploys and verifies only the DonationHandler implementation (no proxy, no upgrade).
+/// Use this when you are not the ProxyAdmin owner: deploy + verify, then give the implementation
+/// address to the owner so they can call proxyAdmin.upgrade(proxy, implementationAddress).
+
+import {DonationHandler} from '../src/contracts/DonationHandler.sol';
+import {Script} from 'forge-std/Script.sol';
+import {console} from 'forge-std/console.sol';
+
+contract DeployDonationHandlerImplementation is Script {
+  function run() external {
+    uint256 deployerPrivateKey = vm.envUint('PRIVATE_KEY');
+
+    console.log('=== Deploying DonationHandler implementation only ===');
+
+    vm.startBroadcast(deployerPrivateKey);
+
+    DonationHandler implementation = new DonationHandler();
+    console.log('Implementation deployed to:', address(implementation));
+
+    vm.stopBroadcast();
+
+    console.log('\n=== Hand off to proxy owner ===');
+    console.log('Give this address to the ProxyAdmin owner to run:');
+    console.log('  proxyAdmin.upgrade(proxy,', address(implementation), ')');
+    console.log('export NEW_IMPLEMENTATION_ADDRESS=', address(implementation));
+  }
+}