v1.12.0 — Workbook chat tools, project libraries, and input hardening

Superseded by 1.14.1. Download the extension from that release.

Tableau Language Support 1.12.0 adds workbook editing through @tableau, conversation history, project instructions, shared workspace calculation libraries, workbook health checks, and conservative unused-calculation cleanup.

This release also hardens workbook text in chat context, validates workbook XML before digesting it, preserves exact parameter names, and treats replacement metacharacters in captions literally.

Validation: 903 unit tests, 24 deterministic feature tests, Windows/macOS/Linux CI, and 15 real VS Code extension-host checks passed. The broader legacy suite still has 23 failures reproduced on the previous commit and a heap-exhaustion issue; these are outside the CI suite.

The attached VSIX is the tested 1.12.0 package and can be installed manually in VS Code. Marketplace publication is pending because the publishing API is timing out and the publisher portal is returning HTTP 429.