feat: explorer API, wallet, CCIP scripts, and config refresh

- Backend REST/gateway/track routes, analytics, Blockscout proxy paths.
- Frontend wallet and liquidity surfaces; MetaMask token list alignment.
- Deployment docs, verification scripts, address inventory updates.

Check: go build ./... under backend/ (pass).
Made-with: Cursor

frontend/next.config.js

@@ -4,8 +4,8 @@ const nextConfig = {
   output: 'standalone',
   // If you see a workspace lockfile warning: align on one package manager (npm or pnpm) in frontend, or ignore for dev/build.
   env: {
-    NEXT_PUBLIC_API_URL: process.env.NEXT_PUBLIC_API_URL || 'http://localhost:8080',
-    NEXT_PUBLIC_CHAIN_ID: process.env.NEXT_PUBLIC_CHAIN_ID || '138',
+    NEXT_PUBLIC_API_URL: process.env.NEXT_PUBLIC_API_URL ?? '',
+    NEXT_PUBLIC_CHAIN_ID: process.env.NEXT_PUBLIC_CHAIN_ID ?? '138',
   },
 }