fix: push on initial install and encode credentials

[merll]

📌 Summary

This PR fixes two issues that were discovered in the course of an installation:

• When the first push attempt to the initial repository fails, it is not reattempted if there are no new commits. This PR changes that behavior for the initial installation.
• The login credentials must be URL-encoded separately for the Git client.

🔍 Reviewer Notes

🧹 Checklist

• Code is readable, maintainable, and robust.
• Unit tests added/updated