undefined Chip, set default to {} for chip-pilot

[KeHang-Zhu]

1. ensure chipValue is set to default {} if undefined
2. use ?. to avoid crashing on undefined values
3. Convert addchip to number before processing in the data export function

• Tests pass
• Appropriate changes to documentation are included in the PR

[google-cla]

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[vivtsai]

We discussed offline and fixed the issue via the following commits:

• df199de
• 758f910