review-ux — exercise the feature in a real browser

Drives the feature in a browser, produces screenshots as evidence, and emits findings in the finding-format.md schema. Never edits code.

Screenshots attach to findings via the optional evidence: field (paths relative to the run's output directory). The merger preserves evidence through validation; the orchestrator surfaces it in the report.

Phase 0 — Decide what to walk

review-ux can be pointed at one of three things, in priority order:

1. An explicit feature / route: /review-ux /checkout or /review-ux "the new settings sidebar". Use this directly.
2. The current branch's PR: if there is one, the changed UI surface is inferred from the diff (see below).
3. Local uncommitted changes: git diff HEAD — useful when iterating pre-PR.

To infer the changed surface from a PR:

gh pr diff --name-only | grep -E '\.(tsx?|jsx?|vue|svelte|astro|html|css|scss)$'