[jjamroga]

Summary

• Apply the Given/When/AssertThat convention from docs(test): add Given/When/AssertThat testing skill #3448 to all 40 matrix scenarios in go/core/internal/a2agateway/http_test.go: conversation retries, missing conversations, URL authority, access failures, share access across transports, push retries, and Agent authorization.
• Give the three single-case tests Given/When/AssertThat function names without adding redundant subtests. The seven matrix-test functions retain short behavior names as grouping labels.
• Preserve the original permutations, setup, assertions, and cleanup. This remains a separate, test-only draft example for discussion; no production behavior or test coverage changes.

Validation

• cd go/core && go run gotest.tools/gotestsum@v1.13.0 --format testname -- ./internal/a2agateway -count=1 — passed, 124 tests.
• make -C go lint LINT_ARGS=./core/internal/a2agateway — passed, 0 issues.
• gofmt -l go/core/internal/a2agateway/http_test.go — passed, no output.
• git diff --check — passed.