refactor(transcription): re-export OnnxTranscriber; note ONNX tier covers NPU+DirectML (P2)

src-tauri/src/transcription/mod.rs

@@ -199,9 +199,10 @@ fn audio_ctx_for_window(n_samples: usize) -> i32 {
     ((window_secs / 30.0) * 1500.0).ceil().clamp(64.0, 1500.0) as i32
 }
 
-// NPU tier (T3.4): Whisper ONNX on the Intel NPU via ONNX Runtime + OpenVINO.
-// A real `OnnxNpuTranscriber` implementing the same `Transcriber` trait; see
-// `npu.rs`. Gated on the `npu` feature so the CPU-only build never pulls `ort`.
+// ONNX tier: Whisper ONNX via ONNX Runtime on the Intel NPU (OpenVINO, T3.4) or
+// a DX12 GPU (DirectML — the non-Vulkan AMD/Intel path, P2). One
+// `OnnxTranscriber` implementing the same `Transcriber` trait; see `npu.rs`.
+// Gated on the `npu` feature so the CPU-only build never pulls `ort`.
 #[cfg(feature = "npu")]
 pub mod mel;
 #[cfg(feature = "npu")]
@@ -209,7 +210,7 @@ pub mod npu;
 #[cfg(feature = "npu")]
 pub mod onnx_models;
 #[cfg(feature = "npu")]
-pub use npu::OnnxNpuTranscriber;
+pub use npu::OnnxTranscriber;
 
 /// Streaming window worker (Phase 1, T1.5/T1.6): accumulates raw 16kHz-mono
 /// chunks from the `audio` service into fixed-size, **non-overlapping** windows