## Summary
`Timer.ClearAllTimers` walked each wheel slot with a `do/while` that read `node._nextTimer` but never advanced `node`. `Stop()` unlinks the head from its slot, so the second pass read a null successor from the same, now-detached node and exited. Only the first timer in every slot was stopped; the rest kept running.
The loop now reads the successor, stops the node, and advances.
Nothing in the repo calls `ClearAllTimers` today, so no running server is affected. It is public API for shards and tests.
## Tests
- `TimerTests.ClearAllTimers_StopsEveryTimerInASlot` puts three timers in the same slot, clears them, asserts none is `Running`, and slices past their due time. It fails without the fix.
- Server.Tests: all pass.
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