fix(BAFB-166): bump @coinbase/cdp-sdk to ^1.48.3

[stephancill]

Summary

Bumps @coinbase/cdp-sdk from ^1.0.0 to ^1.48.3 to fix a missing bs58 dependency error.

Problem: cdp-sdk@1.48.2 imports bs58 but never declared it as a production dependency. It previously resolved via the transitive dep tree of @solana/web3.js, but that package was dropped in cdp-sdk@1.46.0. This causes Module not found: Can't resolve 'bs58' when installing @base-org/account in a fresh project.

Fix: Pin @coinbase/cdp-sdk to ^1.48.3, which added bs58 to its published dependencies.

Ticket: BAFB-166

How did you test your changes?

1. Created a fresh Next.js project, installed @base-org/account@2.5.5 with cdp-sdk@1.48.2 pinned — confirmed Cannot find package 'bs58' error on require('@base-org/account')
2. Built and packed the updated SDK locally, installed in the same project — require('@base-org/account') loads successfully with 14 exports, next build passes

[linear]

BAFB-166

[cb-heimdall]

✅ Heimdall Review Status

Requirement	Status	More Info
Reviews	✅ 2/1	Denominator calculation Show calculation 1 if user is bot 0 1 if user is external 0 2 if repo is sensitive 0 From .codeflow.yml 1 Additional review requirements Show calculation Max 0 0 From CODEOWNERS 0 Global minimum 0 Max 1 1 1 if commit is unverified 0 Sum 1

[github-actions]

Review: No issues found.

This is a clean dependency version bump (@coinbase/cdp-sdk from ^1.0.0 to ^1.48.3) that fixes a transitive dependency resolution failure (bs58 missing at install time). The change is limited to package.json and yarn.lock — no source code, no API surface changes, no bundle size impact (cdp-sdk is external to the browser bundle).

The new transitive Solana dependencies are only relevant for Node consumers of the ./payment/node entrypoint and won't affect the 31 KB browser bundle budget.

PR title conforms to Conventional Commits format — no changes needed.