Add code review and test results

[donvito]

Summary

• Add review-results/code-review-and-test-results.md documenting code review findings.
• Record Go test commands run across the root, standalone packages, and nested modules.
• Note module layout limitations and resource/error-handling recommendations.

Testing

• go version && go test ./... from /workspace (fails: no root Go module)
• go test from /workspace/testing (fails in module mode: no root Go module)
• go test from /workspace/benchmark (fails in module mode: no root Go module)
• GO111MODULE=off go test from /workspace/testing (passes)
• GO111MODULE=off go test from /workspace/benchmark (passes; no tests to run)
• go test ./... from /workspace/http-server (passes; no test files)
• go test ./... from /workspace/htmx (passes; no test files)
• go test ./... from /workspace/ai/go-groq (passes; no test files)
• go test ./... from /workspace/connect-to-db-postgres (passes; no test files)
• GO111MODULE=off go test ./... from /workspace (fails: external deps unavailable in GOPATH mode)
• git diff --check