fix: target production worker for previews
Documentation preview deployment downloads the CI artifact but fails because the configured parent Worker does not exist. Point both preview jobs at opencode-plugins-docs-prod, the name declared by the production stack.
The real deployment must be retried after this trusted workflow reaches the default branch; the production Worker's existence and end-to-end preview remain to be confirmed.
Created with gpt-6.1-terra in Codex.
Summary by cubic
Fixes documentation preview deployments failing because the workflow referenced a parent Worker that doesn't exist. Both preview jobs now target opencode-plugins-docs-prod, which is the name the production stack declares.
The real deployment should be retried once this workflow reaches the default branch; whether previews actually work end-to-end is still to be confirmed.