One type change cascades across 50 files

1. Check the problem

This is TypeScript working correctly, the cascade shows every place that needs to change. Don't suppress with `any` or `@ts-ignore`. Fix the root type first, then work down the list. If it's a rabbit hole, `git stash` and split smaller.

2. Use the prompt

I changed [type] and it cascaded into type errors across many files. Don't use any or @ts-ignore. Walk the errors from the root type outward: fix the source type first, then each dependent error in order. If the change turns out too big to do safely, stop and tell me where to split it.

3. Verify the fix

Review the proposed diff, run the relevant checks and exercise the original failing flow before merging.