Start thread detail data queries eagerly

[ymichael]

Summary

• add an eager non-visual ThreadDetailDataOwner mounted from AppLayout for thread routes
• move thread detail adjunct loading to normal query hooks instead of bootstrap prefetch flags
• remove git work-status / pull-request loading from the eager owner
• defer environment work-status and PR requests until the initial timeline load has settled, so git status cannot sit on the first timeline render path
• keep visible page observers from immediately duplicate-refetching freshly owned data while preserving popout baseline behavior

Validation

• pnpm exec turbo run test --filter=@bb/app -- src/hooks/cache-owners/cache-owner-registry.test.ts
• pnpm exec turbo run typecheck --filter=@bb/app
• dev-browser timing check on /threads/thr_9z4ej99csc showed secondary non-git thread-detail requests starting together at about +232-238ms after the first API request

[ymichael]

Closing per request.