ui-ux-design-principles

Canon for decisions about the USER's experience. The third of the design-principles trio:

• software-design-principles – how a unit of code is written (SOLID, DRY, clean code).
• architectural-design-principles – how the system is shaped (layers, twelve-factor, fitness functions).
• ui-ux-design-principles – how the product looks, behaves, and is navigated, kept testable.

The project's design-guide.{md,json} and ia.md are the per-project instantiation of this canon, the way architecture.json instantiates the layering rules. Markdown only, no scripts: consulted, not invoked. Like the architecture canon, it points each rule at how it's enforced (the E2E/Playwright layer, the design-adherence check against design-guide.json, a11y checks). A rule no test defends is advisory; one a check defends is part of the build.

When to use

• The consort UX Designer imports it to author design-guide.{md,json} + ia.md and define the adherence gate.
• The Driver imports it when building UI that must adhere to the design guide.
• You're reviewing a user-facing change and need a shared vocabulary (heuristics, hierarchy, accessibility) rather than taste.
• You're choosing how the UI is built and need the testability rules (framework choice, stable seams).

UX review checklist (mandatory before promote/merge)