Follow-up to https://github.com/openai/codex/pull/5063
Refined the app-server export pipeline so JSON Schema variants and
discriminator fields are annotated with descriptive, stable titles
before writing the bundle. This eliminates anonymous enum names in the
generated Pydantic models (goodbye Type7) while keeping downstream
tooling simple. Added shared helpers to derive titles and literals, and
reused them across the traversal logic for clarity. Running just fix -p
codex-app-server-protocol, just fmt, and cargo test -p
codex-app-server-protocol validates the change.
a1635eea25