feat: add Codex Responses Lite Rules plugin

[AstroQore]

Plugin

• Repository: https://github.com/AstroQore/cpa-plugin-codex-responses-lite
• Latest release: https://github.com/AstroQore/cpa-plugin-codex-responses-lite/releases/tag/v0.1.0
• Capability: enables CPA's native Codex Responses Lite path for exact provider-prefix/model rules. It prevents CPA's automatic hosted image_generation injection for matching models while continuing to use native routing, credentials, execution, streaming, and usage handling.

Release evidence

• Asset: aq-codex-responses-lite_0.1.0_linux_amd64.zip
• Checksum file: checksums.txt
• Public release readback SHA-256: 29cb164bbfaa023d8472ecd05f025facf81a167aee85ca49b0d6508183c69972
• The checksum entry matches the downloaded asset.
• The zip contains exactly one root-level library: aq-codex-responses-lite.so.

Validation

• This PR changes only registry.json.
• Registry JSON, plugin ID uniqueness, ID format, version format, and repository URL format were validated.
• Plugin CI and release workflows completed successfully for commit d34a5fd.