fix(AIC-3556): publish the Vercel packages when release-please cuts a release

[andrewklatzke]

Summary

• @launchdarkly/ai-vercel-agents and @launchdarkly/ai-vercel-messages are already in release-please-config.json, so the open release (chore: release main #85) will tag them and open GitHub releases.
• The publish workflow never listed those packages, so the npm tarballs would not be published. This adds the same release and manual-publish jobs the other handler packages use.

Test plan

• Confirm the workflow lists packages/vercel-agents and packages/vercel-messages in the dispatch choices, release outputs, and publish jobs.
• Merge this before chore: release main #85. If that release merges first, re-run a manual publish for both packages; release-please will not cut 0.2.0 again.

Made with Cursor

[XieX]

If this is it's first release, shouldn't it release as 0.1 rather than 0.2?

[andrewklatzke]

We're not specifying it anywhere, I think it'll default to the first version. Think that AI comment is unncessary