Regression prevention and quality gates

Problem

The extension's CI pipeline lacks regression gates specific to IDE behavior: there are no automated tests verifying that diagnostics fire correctly for known YAML error patterns, that preview rendering produces expected output for reference dashboards, or that panel interactions (profiler, inspector) don't break across releases. Regressions in diagnostic accuracy or preview fidelity can ship undetected because the test suite focuses on the core compile-execute-render pipeline, not the extension's integration layer. Without automated quality gates that run on every PR and release, each new feature or refactor carries a risk of silently breaking existing behavior for users.

Context

• Manual review is not enough to protect analyst authoring in VS Code/Cursor with preview, diagnostics, and assist once the change rate increases; regressions will keep shipping unless the highest-value checks become automatic.
• This task should identify what needs gating in CI or structured review and what evidence is sufficient to block a risky change before it reaches users.
• Expected touchpoints include apps/ide/vscode-extension/, preview/inspector runtime code, and extension docs/tests, automated tests, eval/QA checks, and any release or review scripts that can enforce the new gates.

Possible Solutions

• A - Add only a few narrow tests around current bugs: easy to land, but it rarely protects the broader behavior contract.
• B - Recommended: define a regression-gate bundle around the core behavior contract: combine focused tests, snapshots/evals, and required review evidence for risky changes.
• C - Depend on manual smoke testing before each release: better than nothing, but too inconsistent to serve as a durable gate.

Plan

1. Identify the highest-risk behavior contracts for analyst authoring in VS Code/Cursor with preview, diagnostics, and assist and the types of changes that should be blocked when they regress.
2. Choose the smallest practical set of automated checks and required review evidence that covers those contracts well enough to matter.
3. Wire the new gates into the relevant test, review, or release surfaces and document when exceptions are allowed.
4. Trial the gates on a few representative changes and tighten the signal-to-noise ratio before expanding the coverage further.

Implementation Progress

Review Feedback

• [ ] Review cleared