ea1a5361e2
The worktree commit 12a6b83 dropped the "Native agy JSON output"
backlog item alongside removing the agy agent. Since we restored
agy in this branch, the TODO is relevant again — agy v1.0.0 still
emits plain text and the prompt-augmentation fallback should be
replaced by --output-format stream-json once the CLI supports it.
Switch TestTryLoadOAuthCredentials_Formats to t.TempDir() to drop
the unchecked os.RemoveAll defer that golangci-lint's errcheck
caught after the merge.