Surface-aware verification

Unit tests prove the code does what its tests say; this skill proves the change works in the running app. It picks the validation that matches what the change actually touches.

1. Detect the surface (from the diff)

Inspect git diff for the change:

• Frontend if it touches rendered UI: .tsx/.jsx/.vue/.svelte/.html/.css/.scss, component or page/route dirs, design tokens, a Storybook, etc.
• API / backend if it touches request handlers, routes, controllers, resolvers, an OpenAPI/Swagger spec, serializers, or lambda handlers.
• A change can be both — validate both surfaces.

If neither surface is present (pure lib/tooling/docs), say so and stop — there is nothing to drive; the unit-test floor is the whole gate.

2. Frontend → chrome-devtools MCP