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
clawbot