What problem does it solve? Intermittent UI bugs, stale state, ordering glitches, and browser-only defects are hard to reproduce and even harder to attribute to a root cause. This Skill provides a disciplined diagnostic workflow that finds the first boundary where correct data becomes incorrect, instead of guessing from symptoms. ## Core Features & Use Cases - Boundary-by-boundary tracing: Compare the same entity across DOM, renderer input, derived state, raw client state, network, and pure transformation layers to locate the first incorrect boundary. - Regression attribution: Replay a minimal sanitized fixture against a suspected commit and its real parent to separate the revision that introduced a latent bug from the data event that exposed it. - Safe isolated reproduction: Builds on the agent-testing workflow for environment isolation, fixture seeding, evidence capture, and teardown, never touching the user's production browser. - Use Case: A user reports that a deleted item reappears after switching tabs. Use this Skill to record the event timeline, compare Zustand state against the SWR cache across remount, and pinpoint the mutation that fails to invalidate the query cache. ## Quick Start Use the debug-frontend-with-browser skill to diagnose why a stale item reappears in the list after navigating away and back.
