debugging-test-failureslisted

# Debugging Test Failures ## Overview This is the shared-skill replacement for the legacy Claude Code `/debug:test` workflow. Use it when tests are failing and the goal is to identify the real root cause instead of making blind changes. ## Read First Before acting, read: - `.agents/skills/debugging-systematically/SKILL.md` - `.claude/skills/test-driven-development/SKILL.md` when the failing test is tied to new feature work or a bugfix ## Core Workflow 1. **Run the relevant test scope** - one file or one pattern when possible - whole-suite only when needed 2. **Parse the failure output** - failing test names - expected vs actual behavior - error messages and stack traces 3. **Check load-sensitivity before diving in** - passes in isolation but fails in the full run - the assertion is about timing, throughput, or sample counts rather than behavior - the failure text names milliseconds, wall-clock boundaries, or "expected N samples" - the file is in a known flake family: harness atomic-write AP-10 (sample-throughput guard, MIN_SAMPLES fixed at 200), RoomLiveLane (wall-clock boundaries), agent-activity (teardown timing), palette-scope-chips (DOR-1502), and the browser spec `apps/e2e/tests/settings/runtimes-tab.spec.ts` "Make default moves the default, and it survives a reload" (DOR-2043: `page.waitForResponse` / `locator.click` 90s timeouts on merge-queue shard 2, three times on 2026-09-14 on diffs tha