Two follow-ups from the voice PR (#70509).
1. macOS ARM64 onnx migration. Existing users who pinned
openwakeword.inference_framework=onnx before the tflite fix landed kept a
wake word that arms but never fires (ONNX's embedding model is broken on
Apple Silicon, upstream #336). New resolve_inference_framework() honors an
explicit framework everywhere ONNX actually works, but coerces the one
provably-dead combination (explicit onnx + macOS ARM64) to tflite with a
one-time warning. No config mutation; empty still falls back to the platform
default. Both read sites (engine init + requirements check) route through
the shared resolver.
2. Voice turn-timeout leak. Each listen cycle reassigned turnTimeoutRef
without clearing the prior 60s timer, so a stale timer from an earlier
cycle could fire handleTurn() mid-way through a later listen — after enough
idle re-listens this wedged the loop into a non-re-arming state (the
'voice chat deactivates after ~a minute' report). Clear before re-arm.
Tests: 64 wake tests (added onnx-coercion / intel-kept / tflite-kept /
empty-default cases; updated the stale 'explicit onnx kept on ARM64' test
that encoded the old broken behavior), 39 desktop voice/wake vitest, tsc +
eslint clean.
