Run 0: Branch Setup — Byproducts

Bug: ((PASS++)) in validate-exit.sh scripts

All validate-exit.sh scripts use set -euo pipefail and ((PASS++)) for counter increment. Under bash strict mode, ((PASS++)) when PASS=0 evaluates to 0 (falsy), causing set -e to exit the script immediately after the first passing check.

Fix: Replace ((PASS++)) with PASS=$((PASS + 1)) and ((FAIL++)) with FAIL=$((FAIL + 1)) in all validate-exit.sh scripts.

Applied to: run-0-branch-setup/validate-exit.sh TODO: Apply the same fix to all other validate-exit.sh scripts before running them (runs 1-9).