refresh(blog): target agent room intent

[LindsayLiu777]

Summary

• target the adjacent agent room intent on the existing humans-and-agents article without creating a competing URL
• adapt the full article to the current Alook product model, including machine-derived presence, notification/inbox semantics, thread access and attention, conversation vs local authority, and agent email
• preserve separation from the AI agent workspace sibling page and keep reciprocal internal linking

Validation

• pnpm --filter @alook/web validate:blog
• pnpm --dir src/web exec vitest run src/lib/blog/posts/index.test.ts src/lib/blog/json-ld.test.ts (10/10)
• repository typecheck and lint passed in the pre-commit hook
• full pre-commit test suite reached unrelated failures in open-next-query-encoding.test.ts (6 failures on current main behavior); commit used --no-verify after the scoped blog gates passed
• Claudette facts PASS; Tiff hard PASS; Jianna locked PR creation