fix: update course-updater to target main instead of staged

[DanWahlin]

Updates the course-updater workflow to target main instead of the deleted staged branch. The PR review step already serves as the review gate, making staged unnecessary.

[Copilot]

Pull request overview

Updates the course-updater agentic workflow configuration to open pull requests against main now that the staged branch has been removed.

Changes:

• Switch create-pull-request.base-branch from staged to main in the workflow source markdown.
• Recompile the generated workflow (course-updater.lock.yml) so safe-outputs config and checkout ref target main.
• Add a new .github/uv-stats.csv file (appears unrelated to the stated PR purpose).

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

File	Description
.github/workflows/course-updater.md	Updates workflow frontmatter and instructions to target main.
.github/workflows/course-updater.lock.yml	Regenerated compiled workflow reflecting main as the base/checkout branch.
.github/uv-stats.csv	New CSV data file added; no references found in repo.

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[Copilot]

This new CSV file appears unrelated to the workflow base-branch change described in the PR, and it is not referenced anywhere in the repo (no code/docs/workflows mention uv-stats). If it’s accidental generated data, please remove it; if it’s intended, add a header/description and a clear consumer (doc or workflow) so its purpose and update process are explicit.