e+05 Resolution

[Olawemi5]

Summary

This fixes REDCap record import serialization for larger numeric record IDs.

Before this change, IDs such as 100000, 200000, and 400000 could be serialized in scientific notation during CSV upload, which could cause REDCap import failures or incorrect record identification.

What Changed

• Added an internal CSV serialization helper for write/import operations.
• Forced non-scientific numeric formatting during upload serialization.
• Updated redcap_write_oneshot() to use the helper.
• Added a focused regression test covering large record ID serialization.

Why This Is Small and Safe

This change is limited to the CSV generation path used for record writes. It does not change the API contract, request shape, or read behavior.

Example

Values like these are now serialized as plain values instead of scientific notation:

• 100000
• 200000
• 400000

[Olawemi5]

I would like these changes checked.