V3 JavaScript/TypeScript test-run capability pack. By-value connector composition (service_kind=cli, no separate ingredient): the local vitest CLI runs one trusted test file, directory filter, or filename:line filter from an explicit project directory cwd and returns plain test output via the javascript.test_run catalog operation. Fixed invocation, but approval-gated: Vitest loads project Vite/Vitest config and executes test, setup, transform, and dependency code, so the run may write caches or project state depending on the project. The pack uses single-run mode, the built-in default reporter, colors disabled, coverage/browser/UI/snapshot-update surfaces disabled, no custom config/root/project/reporter/output-file/watch/debug/list/cache-clear/MCP-like server/browser/shard/changed/typecheck/filter-expression/stdin/shell surface, and a target validation pattern that rejects leading-dash values so the editable target cannot become a Vitest flag. Test failures and no-tests-found outcomes are represented as successful text output; the runner output remains authoritative for distinguishing assertion failures from configuration/runtime errors. Requires vitest on PATH.