Emit stalled socket write timeouts (GOL-389)

[noise64]

• resolves GOL-389
• adds Node-compatible stalled-write timeout checkpoints on top of GOL-360's truthful native TCP write progress and backpressure accounting
• keeps timeout validation and normalization in JavaScript while Rust owns P2/P3 transport progress, waiter lifetimes, and one-shot timeout checkpointing
• rearms only after observed write progress or explicit timeout reconfiguration, and releases P2 pollables before timeout callbacks can destroy a socket
• adds bounded P2/P3 lifecycle coverage for stalled writes, progress, listener reconfiguration, close, and oversized or fractional timeout values
• records the separate test-net-write-slow receiver-end lifecycle gap without claiming that GOL-389 fixes it

Node compatibility

• primary CI-enforced: 3174/4387 (72.4%) → 3174/4387 (72.4%)
• full public: 3174/5750 (55.2%) → 3174/5750 (55.2%)
• node:net: 148 passing and 38 known gaps → unchanged
• the inventory change only replaces the broad reason for test-net-write-slow with its observed pause/resume receiver-end failure; no test is reclassified