Add production Go integrations

[Jason-Doyle]

Summary

• add native Go Git, HTTP, and Kubernetes evidence adapters with validated immutable observations
• add a standard-library GitHub Actions latest-completed-push gate, evidence coverage API, and worldcut-github-ci-go deployment CLI
• add the structural Agentic Data Kernel adapter without a runtime kernel dependency
• add a public constructed-input API that routes Go values through the existing strict ParseInput path
• prepare the backward-compatible ports/go/v0.2.0 module release and runnable Go deployment-gate example

Safety and compatibility

• existing ParseInput, Verify, and VerifyJSON signatures and protocol 0.1 / engine 0.1.2 outputs are unchanged
• redirects are refused, response bodies are closed on all paths, GitHub responses are bounded and strictly validated, strong ETags match the TypeScript grammar, and duplicate validators are never promoted
• parsed inputs, adapter values, ADK values, and verification results are mutation isolated

Quality gate

• all Go packages and both CLIs build and test
• Go race detector and vet pass across every package
• three fuzz targets pass
• 583-case TypeScript/Go/Python/.NET differential suite passes
• live Go and TypeScript GitHub gates agree on main SHA, workflow run, verdict, and requirements
• root release check and actionlint pass