voice_render.rs: new limit_peak_inplace helper (single-pass, allocation-free peak scaler) with 4 unit tests. Applied in both the macOS and iOS render callbacks before the i16 conversion to prevent hard clipping on multi-client mixes that sum past 0 dBFS. Threshold 0.99 keeps the limiter transparent for normal voice levels (sub-millisecond per-frame latency at 48 kHz; pumping risk negligible for speech).
ios_voice_unit.rs: limit_peak_inplace call sites added to the macOS producer/ring render callback (per-frame, 2-element stack array) and the iOS direct-fill_buffer render callback (per-callback, on the scratch_stereo buffer); the downmix helper's hard-clamp is kept as defense-in-depth and is not expected to engage in the integrated flow.
Edison Jwa
74951dd7b4