SQL Database Projects offline install broken; Data Workspace unpublished and docs still point at dead Azure Data Studio

### Description

SQL Database Projects fails to activate in an air-gapped VS Code install:

> Cannot activate the 'SQL Database Projects' extension because it depends on an unknown 'ms-mssql.data-workspace-vscode' extension.

mssql itself works (Connections, Create/Update project from database). The Database Projects view and `Database Projects: New` never appear because Projects never activates.

### Docs and Marketplace still point at Azure Data Studio (retired)

Azure Data Studio support ended 28 Feb 2026. The product is gone. These surfaces still talk as if ADS were the home for this stack:

- Data Workspace Marketplace page: "Microsoft Data Workspace for Azure Data Studio and VS Code" and "This extension is built into Azure Data Studio"
- Install/docs copy that Data Workspace "will be installed automatically" with mssql — that does not happen on VSIX / air-gapped machines
- Users searching for the missing view land on ADS-era wording and assume the VS Code path is abandoned

Please strip ADS from Marketplace descriptions, extension READMEs, and Learn pages for Data Workspace / SQL Database Projects, and replace it with the current VS Code + mssql + Projects install path (including offline VSIX).

### Version mismatch (this is the actual blocker)

| Extension | Latest on Marketplace API |
|---|---|
| `ms-mssql.mssql` | 1.45.1 (2026-08-26) |
| `ms-mssql.sql-database-projects-vscode` | 1.7.0 (2026-08-19) |
| `ms-mssql.data-workspace-vscode` | **0.6.3 (2025-06-18)** |

`https://marketplace.visualstudio.com/_apis/public/gallery/publishers/ms-mssql/vsextensions/data-workspace-vscode/1.45.1/vspackage` 404s.

Only public package:

`https://marketplace.visualstudio.com/_apis/public/gallery/publishers/ms-mssql/vsextensions/data-workspace-vscode/0.6.3/vspackage`

There is no Data Workspace VSIX on the same train as Projects 1.7.0 / mssql 1.45.x. GitHub releases ship `sql-database-projects-v1.7.0` but not a matching `data-workspace-vscode` asset.

### Expected

- Publish Data Workspace on the same cadence as mssql/Projects, with a VSIX on GitHub releases for offline install
- Or stop requiring a separately installed `ms-mssql.data-workspace-vscode` when it is already bundled inside the mssql VSIX
- Remove Azure Data Studio references from Marketplace and docs; ADS is EOL

### Steps to Reproduce

1. Air-gapped VS Code (no Marketplace).
2. Install mssql + SQL Database Projects from VSIX.
3. Reload.
4. Activation error for unknown `ms-mssql.data-workspace-vscode`.
5. No Database Projects view.
6. Guessing Data Workspace 1.45.1 from the mssql version fails; gallery only has 0.6.3.

### Affected Area

- [ ] Connection dialog (SQL Server | Azure browse/Fabric browse)
- [ ] Query editor
- [ ] Query results panel
- [ ] Object Explorer
- [ ] GitHub Copilot integration
- [ ] Preview/Edit data
- [ ] Table Designer
- [ ] Schema Designer
- [ ] Schema Compare
- [ ] Local SQL Server Container provisioning
- [ ] SQL database in Fabric provisioning
- [ ] DACPAC/BACPAC export/import
- [ ] SQL Database projects
- [ ] Query Plan Visualizer
- [ ] Other (please describe below)

### If you selected "Other", please describe the affected area

Data Workspace packaging / Marketplace

### Environment Information

- Air-gapped VS Code
- SQL Database Projects 1.7.0
- SQL Server (mssql) 1.45.x
- Data Workspace missing

### Confirmation

- [x] I have searched existing issues and couldn't find a match
- [ ] I want to work on this issue

Start with the ms-mssql.mssql, ms-mssql.sql-database-projects-vscode, and ms-mssql.data-workspace-vscode extension packages, then compare their activation dependencies and Marketplace versions. Check the GitHub release assets and the listed Marketplace, README, and Learn surfaces; done means an air-gapped VS Code install activates Database Projects and the documentation no longer directs users to Azure Data Studio.

Written by the indexing model from the issue text.