## What changed
- The duration-recording fixture sleep was reduced from a large
artificial delay to `0.2s`, and the assertion floor was lowered to
`0.1s`.
- The shell tool fixtures now force `login = false` so they do not
invoke login-shell startup paths.
## Why this fixes the flake
- The old tests were paying for two kinds of noise that had nothing to
do with the feature being validated: oversized sleep time and variable
shell initialization cost.
- Login shells can pick up runner-specific startup files and incur
inconsistent startup latency.
- The test only needs to prove that we record a nontrivial duration and
preserve shell output. A shorter fixture delay plus a non-login shell
keeps that coverage while removing runner-dependent wall-clock variance.
## Scope
- Test-only change.
1f150eda8b