A script names the files on main that grew by pure appends in more than 10 commits over the last 7 days #6499

Part of #5930, section 1 (append-only registries are where pulls collide; they should become one file per entry).

Done:

• [ ] bun scripts/append-growth.ts [--days 7] [--min 10] reads git log --numstat on the current branch and prints, worst first, each file whose commits in the window only added lines (0 deleted) more than --min times: path and count.
• [ ] The counting is a pure function over parsed numstat rows, tested without git.
• [ ] It never shells out with user text: arguments are validated integers.

Files: scripts/append-growth.ts, a test.

Before pushing: bun x tsc --noEmit and the new test.