Account Socket.IO namespaces skipped corpus

Bun compatibility slice

Account for js/third_party/socket.io/socket.io-namespaces.test.ts at exhaustive corpus position 4055.

Bun currently disables the complete namespace suite with describe.skip. Home should resolve its namespace/runtime and adapter type imports, preserve the suite-level todo, avoid unsupported or allowed-empty classification, expose the namespace constructor surface, and pin the fixture in the permanent third-party matrix.

Tracked from #66.

Implemented and pushed in 0cfee2020.

Home now:

• resolves the namespace fixture's Namespace, Server, Socket, and adapter type imports;
• exports a concrete Namespace class and installs a real root namespace instance at io.sockets;
• retains the namespace socket map, adapter, middleware, broadcast, and reserved-event surfaces;
• corrects the prior Server, Socket rewrite so the runtime Socket constructor is not dropped;
• preserves Bun's intentional suite-level skip and permanently asserts its explicit todo status.

Verification:

• focused position 4055: 1 file, 0 failed, 1 todo, 0 unsupported/allowed-empty;
• Socket.IO positions 4050–4055: 6 files, 13 passed, 7 explicit todos, 0 failed/unsupported/allowed-empty;
• permanent gRPC error-stack, SQL adapter-contract, third-party corpus, and 36-case diagnostic suites all pass.