Address Spec Kit catalog review feedback

[bbjwz]

Summary

• publish the corrected metadata as v0.1.1
• pin the bundle to the Codex integration and align the manifest/catalog description
• make the bundle README self-contained with every required catalog and installation command
• declare the preset's required agentstandards extension and add preset-scoped documentation
• add regression tests for the reviewed publication contracts

Upstream feedback addressed

• Bundle submission #4722
• Preset submission #4721
• Preset catalog review finding

The extension submission has already passed and was merged upstream in spec-kit#4730.

Verification

• Ruff
• 31 pytest tests
• release metadata consistency
• JSON and YAML parsing
• wheel, source archive, extension, preset, and bundle builds
• clean Spec Kit install/validation on 1.0.8 and 1.0.10