Unpublished teams keep a public team page with no members

Summary

Team pages stay publicly reachable after the team is unpublished in the CMS, and they render with an empty roster. /teams/cdp is the example that started this: the CMS record is unpublished and has no members, but the page is still live.

Cause

src/hooks/useTeam.tsx requests the team with publicationState: 'preview' for every visitor, not only for moderators. So unpublishing a team — the action behind the "Unpublish team" button, whose tooltip says the team is removed from the site on the next build — does not take the page off the public site. The page only loses its members, which is what an unpublished team with no profiles looks like.

There is a second, smaller case: a team page with no CMS record at all renders the 404 page, so redirects that pointed at removed teams (/teams/pipeline, /teams/data-warehouse, /teams/video) sent visitors to a dead end.

Affected pages

7 CMS team records have no members:

• Dead teams: cdp, revenue-analytics, actually-ai, and posthog-ai / pipeline (already redirected)
• Active teams that need their record published and members added, not removal: agents, ai-gateway

Related visible effects:

• <SmallTeam /> falls back to printing the raw slug as body text when it cannot find the team, so handbook pages showed content, agents, and ai-gateway mid-sentence.
• The /pipelines product page loads its "Meet the team" section by the team name CDP, so that section renders empty.

Fixes

#20277 archives the dead pages page by page: a redirect to the successor team, removal of the orphaned content, and repair of the three redirects that pointed at dead pages.

Still open after that PR:

1. Request publicationState: 'preview' only for moderators, so unpublishing a team actually removes its public page. This is the fix that makes the class of problem impossible, instead of needing a redirect for each new case.
2. Publish the agents and ai-gateway CMS records and add their members.
3. Point the /pipelines "Meet the team" section at the team that now owns the product. This is a visual change and needs before/after screenshots.