Local streaming STT/TTS with Parakeet + Pocket TTS

- Add provider-agnostic streaming speech interfaces
- Local STT via Sherpa (Zipformer/Paraformer) + Parakeet v3 (offline)
- Local TTS via Pocket TTS ONNX (onnxruntime-node) with chunked streaming
- Auto-download models into PASEO_HOME and add Node download script
- Add E2E download test that round-trips TTS->STT

packages/server/scripts/list-speech-models.ts

@@ -0,0 +1,11 @@
+import { listSherpaOnnxModels } from "../src/server/speech/sherpa/model-catalog.js";
+
+const models = listSherpaOnnxModels()
+  .slice()
+  .sort((a, b) => a.kind.localeCompare(b.kind) || a.id.localeCompare(b.id));
+
+for (const m of models) {
+  // eslint-disable-next-line no-console
+  console.log(`${m.kind}\t${m.id}\t${m.description}`);
+}
+