v0.3.28 - Harden fork PR webhook runs: retry diffs and reuse preinstalled formatters (#907)

🌟 Summary

v0.3.28 makes pull-request automation more reliable when a fork’s latest changes have not yet appeared in GitHub’s comparison API.

📊 Key Changes

• 🔄 Retries fetching pull-request diffs: The automation now retries when a newly pushed fork commit is not immediately available to compare.
• 🛑 Avoids summaries without a verified diff: If the diff still can’t be retrieved, the bot keeps the existing PR summary rather than generating one from only the title or description. First-interaction summaries are also skipped in this case.
• ⚡ Reuses pinned formatters when available: Prettier and shfmt are checked first, and installed only if the expected versions aren’t present. This helps the formatter run in restricted environments where installing tools isn’t allowed.
• 🏷️ Updates the package version to 0.3.28.

🎯 Purpose & Impact

• ✅ Reduces inaccurate or misleading PR descriptions caused by a brief delay after fork updates.
• 🧰 Makes formatting workflows more compatible with unprivileged webhook environments while avoiding unnecessary installs.
• 👀 When GitHub still can’t provide a diff, existing summaries are preserved instead of being replaced with unverified text.

What's Changed

• Harden fork PR webhook runs: retry diffs and reuse preinstalled formatters by @glenn-jocher in #907

Full Changelog: v0.3.27...v0.3.28