Fixed critical bug where validation script exited prematurely under
set -euo pipefail due to arithmetic operations returning non-zero exit
codes when evaluating to 0.
Changes:
- Replaced ((var++)) with var=$((var + 1))
- Replaced ((var += value)) with var=$((var + value))
- Restructured progress indicator to avoid modulo 0 result
Verification:
- Script now successfully validates all 1,260 corpus files
- Correctly reports 603 valid files with complete license info
- Detects 657 files with missing licenses (expected - PDFium test files)
- Exits with code 1 when validation fails (as designed)
Closes bf-632yt
