After a switch, `trackedTokens` and that network's list in `networkTrackedTokens` were one array. So a page's next add or removal also changed `networkTrackedTokens`, and the save wrote that page's older copy over the stored one. Another page's add on the previous network was lost, and its removal was undone. `applyChainSwitchFields()` now copies the incoming network's list. An add or removal on the active network changes only `trackedTokens`. Model: opus-5-5