What problem does it solve? Running tests in this repo is error-prone: CI runs only a narrow backend subset, the frontend lint gate fails on a single warning, and Python 3.12+ interpreters produce misleading event-loop errors. This Skill provides the exact commands to execute, scope, and diagnose tests so local runs match CI behavior. ## Core Features & Use Cases - Targeted Test Execution: Run single files, classes, methods, or keyword-filtered subsets for both pytest (backend) and Vitest (frontend). - CI-Equivalent Local Runs: Reproduce the exact CI invocations, including ruff, typecheck, zero-warning lint, API smoke subset, and quality-contract scripts. - Failure Diagnosis: Read CI failure logs via gh CLI or GitHub MCP tools, confirm pre-existing failures with a git worktree, and recover from truncated output. - Use Case: A backend change touches tag routes — run pytest -q tests/test_tags_routes.py plus the CI subset and ruff before pushing, avoiding a red CI job. ## Quick Start Ask the assistant to run the tests for the file you just changed and reproduce the CI checks locally before pushing.