FOLLOW-UP: Add full case-insensitive field lookup in computed source getField (from PR #215) #218
Description
Context
This follow-up task was identified during the review of PR #215.
Source PR: #215
PR Title: feat: add computed source type for derived/aggregated data
Suggested by: @claude[bot]
Task Description
getField in internal/source/computed.go uses a 3-step lookup: exact match → first-letter titlecase → lowercase. This misses UPPERCASE column names and mixed-case patterns beyond the first letter (e.g., AmountPaid).
A proper case-insensitive scan (strings.ToLower on both key and field) would be more robust. The same applies to getFieldValue in internal/runtime/expr.go which has a similar pattern.
This issue was automatically created by prmonitor from PR review comments.