Motivation:
- App-server JSON schema output is already stable; sorting object keys is unnecessary.
- Alphabetical key canonicalization is potentially harmful because it obscures intentional ordering (e.g. struct field order) and makes diffs noisier.
What changed:
- Remove JSON key-sorting from schema emission.
- Regenerate vendored JSON schema fixtures.
Refs: openai/codex#8956 (fixture sync test pattern)
