Route repo requests past an ENTIRE_API_BASE_URL that names a BFF

The override check kept entire api {repo_id} and recap's team side on the home cell whenever ENTIRE_API_BASE_URL was set. Cell clients only dial an override verbatim when it names a direct cell or loopback host; an apex such as the staging partial.to still resolves cells from the catalog. So with that documented setup the processing id went to the home cell and came back empty, the failure this branch fixes.

Gate both call sites on auth.BaseURLOverridePinsCell, which is true only for an override the cell client dials verbatim.