#13585: fix: .gitignore `.tgz` → `*.tgz` glob pattern

## Summary Resubmitting [#12391](https://github.com/openclaw/openclaw/pull/12391) — previous PR was auto-closed when the fork was deleted and recreated. `.tgz` in `.gitignore` only matches a file literally named `.tgz`. Changed to `*.tgz` so tarballs from `npm pack` are properly ignored. ✍️ Author: Claude Code with @carrotRakko (AI-written, human-approved) <!-- greptile_comment --> <h2>Greptile Overview</h2> <h3>Greptile Summary</h3> Fixed `.gitignore` pattern from `.tgz` to `*.tgz` so that tarball files generated by `npm pack` are properly ignored. The previous pattern `.tgz` only matched a file literally named `.tgz`, not actual tarball files like `openclaw-1.0.0.tgz`. <h3>Confidence Score: 5/5</h3> - This PR is safe to merge with no risk - The change is a trivial `.gitignore` fix that corrects an obvious mistake in the glob pattern. The pattern `.tgz` without the wildcard would only match a file literally named `.tgz`, not actual npm tarball files like `package-name-1.0.0.tgz`. Changing it to `*.tgz` properly ignores all tarball files as intended. - No files require special attention <!-- greptile_other_comments_section --> <!-- /greptile_comment -->