feat(paths): DirectML runtime dir/dll/ready helpers (P2)

src-tauri/src/paths.rs

@@ -63,6 +63,26 @@ pub fn npu_runtime_ready() -> bool {
     npu_runtime_dll().exists()
 }
 
+/// On-demand DirectML runtime (ONNX Runtime built with the DirectML EP, P2).
+/// The non-Vulkan GPU path for AMD/Intel reuses the same Whisper-ONNX model as
+/// the NPU path but needs a *different* `onnxruntime.dll` — Intel's OpenVINO ORT
+/// build doesn't carry the DirectML EP — so it lives in its own runtime dir.
+/// `DirectML.dll` itself ships with Windows 10 1903+, so the bundle is just ORT.
+pub fn directml_runtime_dir() -> PathBuf {
+    wa_root().join("runtime").join("directml")
+}
+
+/// The dlopen target for `ort` (load-dynamic) on the DirectML path; its presence
+/// is the readiness signal that gates AMD/Intel non-Vulkan availability.
+pub fn directml_runtime_dll() -> PathBuf {
+    directml_runtime_dir().join("onnxruntime.dll")
+}
+
+/// True once the DirectML runtime has been staged (P2).
+pub fn directml_runtime_ready() -> bool {
+    directml_runtime_dll().exists()
+}
+
 /// Fixed filenames pending T4.7 (diarization model management/selection in Settings).
 pub fn diarization_segmentation_model_file() -> PathBuf {
     models_dir().join("seg-pyannote-3.0.onnx")