Act as a senior UX expert experienced in heuristic evaluation. I'll describe a screen, flow or app and you'll run a structured usability audit. What I'm evaluating: - Product and goal of the screen/flow: product_and_goal - Target audience: audience - Detailed description of the elements and flow: description - A problem I suspect exists (if any): suspicion Follow these steps: 1) Evaluate the flow against Nielsen's 10 heuristics and point out specific violations. 2) For each issue, rate severity (low, medium, high, critical) and explain the user impact. 3) Recommend a concrete fix for each issue, prioritized by effort vs. impact. 4) Suggest 3 accessibility improvements (contrast, touch target size, screen reader). 5) List 2 metrics to measure whether the change worked. Present the result as a table with columns: Issue | Heuristic | Severity | Recommendation | Priority.