feat(voice): add iOS VAD runtime support

crates/chanora_audio/src/lib.rs

@@ -15,26 +15,36 @@
 //! * Push-to-talk: capture stream is permanently open; encoding is
 //!   gated by an atomic `ptt_active` flag
 //!
-//! ## What's NOT wired in this Beta
+//! ## Voice processing in this Beta
 //!
-//! * AEC / AGC / NS / HPF DSP chain (DEC-007/008/009/010 — Beta+
-//!   work; the toggles in `AudioEffects` are honoured by *naming*
-//!   but the filters are no-ops)
-//! * Hot-plug device-change handling
+//! * iOS/macOS use Apple's VoiceProcessingIO path, which owns platform
+//!   AEC / AGC / noise suppression for the shipping route.
+//! * Rust owns VoiceActivity transmit gating and exposes a software
+//!   processor surface for debug/future raw routes.
+//! * Hot-plug device-change handling is still platform-specific follow-up work.
 //! * Sample-rate adaptation if the device cannot do 48 kHz / mono in
 //!   the format we request (returns `AudioError::StreamConfig`)
 //! * Multi-channel speaker layouts beyond stereo
 
 #![warn(missing_docs)]
 
+pub mod audio_processing;
+pub mod debug_wav;
 mod engine;
+pub mod frame;
 pub mod mobile_voice_backend;
 pub mod mode_stack;
+pub(crate) mod opus_voice;
+pub mod processor;
 pub mod ptt;
 pub mod ptt_backends;
 pub mod release_tail;
+pub mod route_policy;
 pub mod transmit_mode;
 pub mod transmit_selector;
+pub mod vad;
+pub mod voice_activity;
+pub(crate) mod voice_render;
 
 #[cfg(target_os = "linux")]
 mod sdl_output;
@@ -42,9 +52,16 @@ mod sdl_output;
 #[cfg(any(target_os = "ios", target_os = "macos"))]
 mod ios_voice_unit;
 
+#[cfg(target_os = "ios")]
+pub mod ios_raw_unit;
+
 #[cfg(target_os = "android")]
 pub mod android_voice_unit;
 
+pub use audio_processing::{
+    AudioBackend, AudioProcessingConfig, AudioProcessingStats, AudioRoute, EffectOwner,
+    IosVoiceProcessingMode, SharedAudioProcessingStats, VadBackend,
+};
 pub use engine::{AudioEngine, AudioEngineConfig};
 
 // SDD-120 §3 bench seam — `#[doc(hidden)]` re-export so the criterion
@@ -88,14 +105,20 @@ pub enum AudioError {
     /// been called before `voice_join` triggers the audio engine.
     #[error("android platform not ready: ndk_context not initialised")]
     PlatformNotReady,
+    /// Audio processing config failed validation.
+    #[error("invalid audio processing config: {0}")]
+    InvalidAudioProcessingConfig(String),
+    /// Requested audio processing config is schema-visible but not implemented.
+    #[error("unsupported audio processing config: {0}")]
+    UnsupportedAudioProcessingConfig(String),
 }
 
 /// Audio-effect toggles. Defaults match DEC-007 (AEC),
 /// DEC-008 (AGC), DEC-009 (NS), DEC-010 (HPF) — all enabled.
 ///
-/// Note: in Beta v0.2.0-beta.1 the actual DSP filters are not yet
-/// implemented; the struct is kept here as the public API surface so
-/// later work can flip an internal flag without breaking callers.
+/// On iOS/macOS these map to VoiceProcessingIO-owned effects in the
+/// default route. Software processor backends may also consult them
+/// on raw/debug routes.
 #[derive(Debug, Clone, Copy)]
 pub struct AudioEffects {
     /// Acoustic echo cancellation (DEC-007).