test(uvai): add browser-boundary verification for the hybrid workspace #2202

Source artifact

Merged PR #2184 / commit b4728bf introduced the UVAI hybrid workspace prototype.

The final implementation repaired the reviewed credential, sandbox, escaping, branding, terminal-input, and ticket-copy defects. However, the current-head review still identified an uncovered browser/DOM execution surface, and the repository only runs logic.test.mjs for pure helpers.

Why this remains material

This surface accepts editable HTML, CSS, JavaScript, Markdown, terminal commands, and assistant prompts, then renders into both a sandboxed preview and parent-page chat. Unit-only helper coverage does not prove that the actual DOM boundary, model updates, sandbox flags, and visible actions behave as claimed.

The prototype is also a sibling surface while /studio remains canonical. That is acceptable only if it stays explicitly prototype-only until an integration or redirect decision is made.

Fixture-only acceptance criteria

• Add deterministic browser/DOM tests for Embed, Summarize, Extract, Escalate, free-form Ask, and terminal command input.
• Prove edited Monaco models update the preview and summary from current content rather than starter constants.
• Prove lesson/editor markup is escaped before entering parent-page innerHTML.
• Prove the preview retains sandbox="allow-scripts" without allow-same-origin, top navigation, popups, downloads, or parent credential access.
• Cover closing-script sequences, reordered asset attributes, missing virtual assets, and repeated edits.
• Prove no gateway key or production credential is read from or written to window, preview storage, query strings, or receipts.
• Record whether this directory remains a prototype, redirects into /studio, or is integrated as a canonical studio pane.
• Add a machine-readable test receipt tied to the exact head and keep production Gateway calls disabled.

Boundary

No deployment, live provider invocation, public compatibility claim, or production activation is required. Keep this fixture/browser-test only until the canonical-surface decision is reviewed.