feat: js-libp2p compatibility — zero-copy JSI data path + Node net.So…

[tswindell]

…cket half-open parity (#209)

Fixes #209 (Task 2: RN clients failing to connect to libp2p bootstrap/relay/peer nodes with UnexpectedEOFError). Task 1 (#183, net.createServer(options, cb)) is already resolved as of v6.4.1 — no code change needed.

Root-caused four independent defects that made js-libp2p v3 unusable on Android RN 0.83 (New Arch / bridgeless / Hermes), each device-proven on a physical device (Nokia 8.3 5G, arm64-v8a) against the public Amino DHT swarm:

1. connect() option-graph OOM. @libp2p/tcp spreads its entire cyclic dial-options object (signal/upgrader/components) into the net.connect() arg; RN's jsi::dynamicFromValue recursively explodes it into millions of folly::dynamic nodes → Scudo OOM in seconds. Fixed with an explicit scalar allow-list (the native side only ever reads those keys).

2. Per-chunk legacy-bridge data path OOM. Any per-chunk crossing of the RCTDeviceEventEmitter / invokeJavaMethod bridge backlogs unbounded folly::dynamic under libp2p volume. Replaced inbound + outbound byte movement AND the readable/written signals with a zero-copy JSI HostObject (cpp/TcpDataBridge) driven by the C++ CallInvoker — bytes and signals never transit folly::dynamic.

3. JNI registration lifetime. In the New-Arch single-merged-.so model the data-bridge JNI_OnLoad ran pre-bundle under the bootstrap classloader; native methods failed to bind. Fixed with an implicitly-bound, Java-driven install entry + a link-time keep anchor (defeats --gc-sections stripping of the runtime-only TU).

4. JSI install guard on a HostObject. The "callback installed" guard was stashed as a property on the JSI HostObject; Hermes rejects arbitrary-property writes on a HostObject with a default setter (TypeError), which was swallowed → bridge null → every noise write failed → every dial silently abandoned (conns=0). Moved the guards to module-level state.

Also implements the Node net.Socket half-open / teardown contract @libp2p/tcp depends on (and which the bounty's connect failure surfaces):

• connect() now reads options.allowHalfOpen (kept off the native bridge — JS lifecycle flag only).
• Adds socket.destroySoon() (libp2p sendClose calls it on every graceful close — its absence threw is not a function on every connection teardown).
• Adds socket.resetAndDestroy() (libp2p sendReset).
• 'close' now emits a boolean hadError per the Node spec (was the raw error object, working only by truthiness).
• destroy(error) accepts an optional error per the Node signature.

iOS JSI parity is a scoped follow-up: the shared JS changes are iOS-correct, but the C++ data path is not yet wired into the iOS pod. The legacy iOS path is unaffected; only the new zero-copy JSI path is Android-only for now.

Adds tests/halfOpen209.test.js (6 tests). Full suite green (16/16). No version bump (release is the maintainer's call). Server.js / index.js / TLS*.js intentionally untouched.