Add explorer URL and address environment variables

- Add EXPLORER_URL with Sepolia Etherscan default
- Add ORGANIZATION_REGISTRY_ADDRESS and PROCESS_REGISTRY_ADDRESS
- Configure environment variables in Vite build process

Author: marcvelmer

examples/ui/vite.config.ts

@@ -13,6 +13,9 @@ const viteconfig = defineConfig(({ mode }) => {
     define: {
       'import.meta.env.API_URL': JSON.stringify(process.env.API_URL || 'https://sequencer1.davinci.vote'),
       'import.meta.env.RPC_URL': JSON.stringify(process.env.RPC_URL || ''),
+      'import.meta.env.EXPLORER_URL': JSON.stringify(process.env.EXPLORER_URL || 'https://sepolia.etherscan.io'),
+      'import.meta.env.ORGANIZATION_REGISTRY_ADDRESS': JSON.stringify(process.env.ORGANIZATION_REGISTRY_ADDRESS || ''),
+      'import.meta.env.PROCESS_REGISTRY_ADDRESS': JSON.stringify(process.env.PROCESS_REGISTRY_ADDRESS || ''),
     },
     resolve: {
       alias: {