feat: web3 deps update

[rin-st]

Summary

Part 2 of #1279

Updates web3 dependencies in packages/nextjs:

• viem 2.39.0 → 2.48.4
• @rainbow-me/rainbowkit 2.2.9 → 2.2.10
• wagmi stays on 2.19.5

Why wagmi stays on v2

Wagmi v3 is out, but RainbowKit doesn't support it yet — it still pins wagmi v2. Bumping wagmi alone breaks the connector types.

Note: ConnectKit and Reown AppKit (ex-Web3Modal) also haven't shipped wagmi v3 support, so swapping the kit wouldn't unblock the upgrade.

Code changes from the viem bump

• publicClient.getBytecode(...) → publicClient.getCode(...) (renamed in viem) in ContractTabs.tsx and useDeployedContractInfo.ts
• Enabled @typescript-eslint/no-deprecated in eslint.config.mjs to catch future viem/wagmi deprecations early
• Fixed stale JSDoc useContractRead → useReadContract in useScaffoldReadContract.ts

Test plan

• yarn next:check-types clean
• yarn next:lint clean
• yarn start + connect via MetaMask, WalletConnect, burner — read/write contract works
• Block explorer detects EOA vs contract correctly (verifies getCode swap)

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Waits for

• Deps: next 15 → 16 and minor frontend updates #1280
• hardhat v3 migration #1272
• Bump viem/rainbowkit/react-query + fix Next.js SSR errors from new WalletConnect burner-connector#54. burner-connector is currently a local path link — switch back to a published version before merging.