fix(ci): build lib/ before publishing to npm

[alexchavez1]

Description of this change

Fix CI release job that has been publishing tarballs missing the lib/ directory since v0.10.3, causing MODULE_NOT_FOUND errors for all npm consumers.

• Add npm run prepare step to the release job so lib/ is built before npm publish runs
• Add Verify tarball contains lib/ step to the build job that asserts lib/commonjs/index.js, lib/module/index.js, and lib/typescript/src/index.d.ts are present in the would-be tarball on every PR

Why is this change being made?

• Chore (non-functional changes)
• Bug fix (non-breaking change that fixes an issue)
• New feature (non-breaking change that adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

How was this tested? How can the reviewer verify your testing?

Tested Locally:

• Confirmed @ketch-com/ketch-react-native@0.19.0 (latest published) is missing lib/ — node -e "require('@ketch-com/ketch-react-native')" throws MODULE_NOT_FOUND on a clean install
• Simulated the release runner locally: npm ci --ignore-scripts && npm run prepare && npm pack --dry-run — confirmed lib/commonjs/index.js and lib/module/index.js appear in the tarball listing
• Verified npm run prepare builds all 3 targets (lib/commonjs, lib/module, lib/typescript) successfully

Related issues

Checklist

• I have added tests to cover my changes.
• All new and existing tests passed.
• Add screen recording (learn how to)
• I have evaluated the security impact of this change, and OWASP Secure Coding Practices have been observed.
• I have informed stakeholders of my changes.

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Note

Low Risk
Low risk: workflow-only changes that ensure build artifacts are produced and included in the package tarball; main failure mode is a CI/release pipeline break rather than runtime behavior changes.

Overview
Ensures published npm tarballs include the built lib/ outputs by running npm run prepare in the release job before npm publish.

Adds a CI guard in the build job that runs npm pack --dry-run and fails if expected lib/commonjs, lib/module, and TypeScript .d.ts entries are missing from the would-be tarball.

^{Reviewed by Cursor Bugbot for commit 998bce2. Configure here.}