Reliable DSH CI tests

Build tests that remain correct under the repository's real CI topology, not only when run alone on a quiet workstation. This skill owns isolation and reliability decisions; it does not replace the repository's test-tier policy or select every command for a push.

Read the owning rules

• Use the testing policy to select unit, coverage, expected-output, snapshot, browser, or real-API evidence.
• Use the defensive patterns for lifecycle, subprocess, cancellation, and teardown behavior.
• Read the active Vitest config and GitHub workflow when their worker or job topology affects the test.
• For recorded-session scenarios, also follow the snapshot instructions.
• Use dsh-pre-push-checks after the test design is sound to select outgoing validation.

Model the execution topology

Assume these layers can overlap unless the active configuration proves otherwise: