chore: update Kody template to eve 0.73.0

Summary

Kody uses eve 0.39 and AI SDK 7.0.70, which predate current APIs. Upgrade eve and its AI SDK/Chat SDK peers, and route research through a workflow tool so structured output is requested on the child session's send() call.

Validation

• LINEAR_CONNECTOR=linear/kody-agent RESEND_FROM_ADDRESS=kody@example.com RESEND_API_KEY=re_test DIGEST_REPO=vercel/eve DIGEST_EMAIL=team@example.com REDIS_URL=redis://localhost:6379 pnpm validate passed with 0 discovery errors or warnings.
• pnpm peers check passed.
• git diff --check passed.

Checklist

• This change was requested or approved by a maintainer
• I ran the relevant checks from CONTRIBUTING.md
• I added tests and documentation where relevant
• I added a changeset if this touches the published eve package
• DCO sign-off passes for every commit (git commit --signoff)