docs: dbt chat-driven workspace authoring (validation, file R/W, publish) is undocumented

## What's missing

A cluster of PRs in cubedevinc/cubejs-enterprise shipped full conversational dbt authoring from Cube AI chat, well beyond what's currently documented:

- #14392 `feat(dbt): add validation schema execution` — tier-2 dbt validation (parse/compile/build) in a customer-owned validation schema with safe teardown
- #14219 `feat(ai-engineer): drive the full dbt pull from Cube AI chat`
- #14198 `feat(ai-engineer): read the dbt sync history — list, detail, and logs`
- #14274 `feat(ai-engineer): run dbt, read and write files in a dbt workspace`
- #14298 `feat(ai-engineer): expose dbt workspace agent tools`
- #14351 `feat(ai-engineer): publish dbt workspace changes`
- #14268 `feat(ai-engineer): dbt workspace lifecycle service`
- #14184 `feat(ai-engineer): dbt sync history — design + persistence`
- #14345 `expose dbt sync history on the public REST API` (labeled `chore` but is a new public API surface)

Together: users can author, validate (safely, in a customer-owned schema), run, and publish dbt models conversationally through chat, with structured sync history — not just trigger an existing sync.

`docs-mintlify/docs/integrations/dbt.mdx` currently documents only the pull-triggering slice under "Trigger from Analytics Chat": asking the agent to check for/pull dbt updates, and asking "what happened with my recent dbt syncs?" for a chat-based Q&A answer. It does **not** cover: validation-schema execution, conversational file read/write in a dbt workspace, a structured sync-history UI (list/detail/logs) versus just chat Q&A, or publishing workspace changes via chat.

## Why this needs a ticket instead of a docs PR

This is a substantial, multi-capability feature area (comparable in scope to a full "dbt Workspace" section), not a one-paragraph edit to the existing page — it needs several new subsections (or a dedicated page) and someone with hands-on access to the shipped feature to describe the actual UX accurately (per the customer-facing-criteria rule to verify real behavior against the PR/diff rather than the commit subject alone).

## Suggested scope

- Expand `docs-mintlify/docs/integrations/dbt.mdx` (or split into a new page if it grows large) to cover: validation-schema execution and its safety guarantees, conversational workspace file read/write, the structured sync-history view, and publishing workspace changes from chat.
- Cross-link from the AI/chat docs (`docs/explore-analyze/analytics-chat.mdx`) if the capability is discoverable from there.

Filed as a GitHub issue rather than a Linear ticket because the Linear MCP connector isn't authorized in this session — recommend re-filing in Linear (or linking this issue there) once available.

Start by reading docs-mintlify/docs/integrations/dbt.mdx, docs/explore-analyze/analytics-chat.mdx, and the referenced PRs to verify the shipped behavior with hands-on access. Document validation, workspace file access, sync history, and publishing, adding a cross-link where appropriate; done means users can understand and use each capability accurately.

Written by the indexing model from the issue text.