fix(ci): rebase-and-retry auto-commit pushes to survive races

[AbdullahBakir97]

Summary

The morning health-check on main after commit 8217205 showed Build examples failing with ! [rejected] main -> main (fetch first) — classic push race against Refresh CONTEXT.md which fired off the same merge.

Fix: replace bare git push with a 3-attempt loop:

for attempt in 1 2 3; do
  if git pull --rebase origin main && git push; then exit 0; fi
  sleep 3
done
exit 1

Applied symmetrically to both build-examples.yml and refresh-context.yml. Both auto-commits are purely additive (CONTEXT.md and examples/rendered/ never touch each other), so rebase has no conflicts.

Test plan

• Both workflow YAMLs parse cleanly via yaml.safe_load
• CI green on push (preview)
• Verify in production: next push to main should fire both workflows simultaneously and both should now succeed