Review caught a second-order effect of the fix: making the leaked-timer net
global invalidated the rationale of a neighbouring rule.
"Do not hand-roll a bare MantineProvider — that reintroduces the leak class"
stopped being true the moment the net moved into setup.ts, which covers every
unit test regardless of how it renders. The rule itself is still right, so keep
it and replace the justification: a hand-rolled provider skips the project theme
and the helper's options and drifts from every other test. Both copies say
explicitly that the old reason no longer holds, so nobody re-derives it.
Mirrored into .github/copilot-instructions.md in the same PR, as AGENTS.md
requires for review-relevant guidance — it carried the identical stale claim.
That makes four places this one belief had propagated to. A fix can create stale
docs by making a previously-true statement false, which is easy to miss when
only the changed lines get read.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01HDdo1rNRVQnVRRdsqSrvG3
Signed-off-by: cliffhall <cliff@futurescale.com>
b451949c9e