Port Azure Service Bus module and credential-gated test contracts

Context

The sequential Bun corpus frontier has advanced through SQL/TLS and wire-frame coverage to js/third_party/@azure/service-bus/azure-service-bus.test.ts at position 3948/4708. This contributes to #66.

First observed gap

The corpus runner currently classifies this TypeScript module as unsupported module syntax before it can register the credential-gated describe.skipIf(!azureCredentials) suite. The file combines a scoped bare-package import, the harness secret helper, and a TypeScript non-null assertion on the connection string.

Acceptance criteria

• The module prepares and evaluates without an unsupported-syntax classification.
• Scoped @azure/service-bus resolution follows the Bun corpus package/fixture contract.
• TypeScript non-null assertion lowering preserves the constructor argument.
• Missing TEST_INFO_AZURE_SERVICE_BUS credentials produce the expected TODO/skip without network access.
• When credentials are available, sender/client close behavior and error cleanup remain representable.
• Pin the exact corpus result in an appropriate permanent third-party gate.

Completed on main in 29a8374f92116438e7eeb48b4a92b61d5b58f7cc (feat(third-party): port Azure Service Bus contracts).

Results:

• js/third_party/@azure/service-bus/azure-service-bus.test.ts: 0 failed, 0 unsupported, 1 expected credential-gated TODO.
• Scoped package import resolution now recognizes @azure/service-bus; TypeScript non-null assertion lowering and harness getSecret work together correctly.
• The Service Bus shim preserves client/sender construction, validation, send, close, and closed-resource error behavior.
• The exact result is pinned in the permanent third-party JWT/utility mini-suite, which passes in full.

The sequential frontier advances through 3948/4708. DuckDB Node API coverage is tracked separately in #209.