feat: add Gemini OpenAI Normalizer plugin

[licoba]

Plugin

• Repository: https://github.com/licoba/cpa-plugin-gemini-openai-normalizer
• Latest release: https://github.com/licoba/cpa-plugin-gemini-openai-normalizer/releases/tag/v0.1.2
• Release tag: v0.1.2

Release evidence

The release contains checksums.txt and store-compatible archives for:

• Linux amd64 / arm64 (GLIBC 2.17-or-older baseline)
• Darwin amd64 / arm64
• Windows amd64 / arm64
• FreeBSD amd64

Each archive contains exactly one root-level library named gemini-openai-normalizer.so, .dylib, or .dll. All checksums, binary formats, target architectures, and ABI exports have been verified.

Capability

The plugin normalizes Gemini OpenAI Chat Completions and Responses output without changing non-Gemini client traffic:

• official chatcmpl- ID prefix;
• client-requested model alias restoration using the ABI RequestedModel field;
• reasoning-token accounting in completion/output totals without double counting compliant usage;
• raw JSON and SSE streaming chunks, including frames split across ABI callbacks and complete SSE data lines without trailing newlines.

Validation

• go test -race ./...
• go vet ./...
• all seven platform builds completed successfully;
• Linux amd64 and arm64 artifacts pass the GLIBC 2.17 symbol-version gate;
• release archive layouts and SHA-256 checksums verified;
• production CPA and LinuxDo Hub end-to-end matrix passed for all four published Gemini models across Chat, Chat streaming, Responses, and Responses streaming.