Discord enforces a hard 100-command limit per app and rejects an upsert that would push the live total over 100 (error 30032), which silently breaks ALL slash commands. The sync deleted obsolete commands AFTER creating new ones, so an app already at the cap momentarily exceeded it and the whole sync failed.
Reorder: delete no-longer-desired commands up front, then create/update. Removes the now-redundant trailing delete loop. Adapts @infinitycrew39 PR #50890 to current main (the original adapter diff no longer applied after the platform refactor); test commit cherry-picked with authorship preserved.