QVAC-17876 feat[bc]: migrate SDK parakeet transcription to 0.6.0 GGML

.gitignore

@@ -15,6 +15,12 @@ packages/sdk/bun.lock
 NOTICE_LOG.txt
 NOTICE_FULL_REPORT.txt
 
+# Local TTS / transcription example output artifacts (generated by
+# packages/sdk/examples/**). Never commit these — they're large WAVs
+# produced by running the demos locally.
+packages/sdk/*-output.wav
+packages/sdk/examples/**/*-output.wav
+
 # Slack/Discord copy-paste announcement posts generated by the
 # changelog skill (see scripts/sdk/generate-changelog-sdk-pod.cjs
 # --generate-announcement-post). These are local working artifacts,

docs/website/content/docs/ai-capabilities/transcription.mdx

@@ -6,11 +6,11 @@ schemaType: HowTo
 
 ## Overview
 
-Transcription uses your choice of either [`qvac-ext-lib-whisper.cpp`](https://github.com/tetherto/qvac-ext-lib-whisper.cpp) or [NVIDIA Parakeet](https://huggingface.co/nvidia/parakeet-tdt-0.6b-v2) (via [ONNX Runtime](https://onnxruntime.ai)) as inference engine. Load a model using `modelType: "whisper"` for `qvac-ext-lib-whisper.cpp`, or `modelType: "parakeet"` for Parakeet. Parakeet supports multilingual transcription (TDT), english-only transcription (CTC), and speaker diarization (Sortformer).
+Transcription uses your choice of either [`qvac-ext-lib-whisper.cpp`](https://github.com/tetherto/qvac-ext-lib-whisper.cpp) or [NVIDIA Parakeet](https://huggingface.co/nvidia/parakeet-tdt-0.6b-v3) (via the GGML-based [`parakeet-cpp`](https://github.com/tetherto/qvac-ext-lib-whisper.cpp/tree/main/parakeet-cpp) engine) as inference engine. Load a model using `modelType: "whisper"` for `qvac-ext-lib-whisper.cpp`, or `modelType: "parakeet"` for Parakeet. Parakeet supports multilingual transcription (TDT), english-only transcription (CTC), speaker diarization (Sortformer), and end-of-utterance detection (EOU) for duplex streaming.
 
 Provide audio input as `audioChunk`, either as a file path (string) or an in-memory audio buffer.
 
-`transcribe()` returns the full transcription as a single `string`. If you need partial results as they become available, use `transcribeStream()` to receive text chunks in real-time.
+`transcribe()` returns the full transcription as a single `string`. If you need partial results as they become available, use `transcribeStream()` to receive text chunks in real-time. Both whisper and parakeet expose duplex `transcribeStream()` sessions; see "Streaming with `transcribeStream()`" below.
 
 ## Functions
 
@@ -31,23 +31,84 @@ You should load two models:
 
 ### Parakeet
 
-Parakeet requires multiple model artifacts. The required files depend on the model variant:
-- **TDT** (multilingual, ~25 languages): encoder, encoder data, decoder, vocabulary, and preprocessor files.
-- **CTC** (english-only): model, model data, and tokenizer files.
-- **Sortformer** (speaker diarization): a single model file.
+As of `@qvac/transcription-parakeet` 0.6.0, Parakeet ships as a **single GGUF** per variant — the addon auto-detects TDT / CTC / Sortformer / EOU from `parakeet.model.type` GGUF metadata. There is no `modelConfig.modelType` discriminator, no per-variant `parakeet*Src` artifact fields, and no `ParakeetArtifactsRequiredError`. Just supply the GGUF via the top-level `modelSrc`:
 
-Pass the model variant via `modelConfig.modelType` (`"tdt"`, `"ctc"`, or `"sortformer"`) and provide the corresponding source fields in `modelConfig`. See [`loadModel()` — Parakeet `modelConfig`](/reference/api#loadmodel).
+```ts
+await loadModel({
+  modelSrc: PARAKEET_TDT_0_6B_V3_Q8_0,    // multilingual, ~750MB
+  modelType: "parakeet",
+});
+
+await loadModel({
+  modelSrc: PARAKEET_CTC_0_6B_Q8_0,       // english-only, streaming-capable
+  modelType: "parakeet",
+});
+
+await loadModel({
+  modelSrc: PARAKEET_SORTFORMER_4SPK_V1_Q8_0,  // 4-speaker diarization
+  modelType: "parakeet",
+});
+
+await loadModel({
+  modelSrc: PARAKEET_EOU_120M_V1_Q8_0,    // end-of-utterance detection
+  modelType: "parakeet",
+});
+```
 
 For model artifacts available as constants, see [SDK — Models](/introduction#models).
 
-<Callout type="success">
-**Tip:** if you are not using SDK model constants, download the required files from a compatible model repository — e.g., [`parakeet-ctc-0.6b-ONNX` on Hugging Face](https://huggingface.co/onnx-community/parakeet-ctc-0.6b-ONNX/tree/main/onnx). For a list of compatible repositories, see [Addons — Parakeet](https://github.com/tetherto/qvac/tree/main/packages/transcription-parakeet#models).
+<Callout type="info">
+**Migrating from pre-0.6 Parakeet (ONNX multi-file):** the legacy multi-file ONNX `modelConfig` shape (`parakeetEncoderSrc` / `parakeetDecoderSrc` / `parakeetVocabSrc` / `parakeetPreprocessorSrc`, plus `parakeetCtcModelSrc` / `parakeetTokenizerSrc` and `parakeetSortformerSrc` for the CTC/Sortformer variants) is no longer supported. Passing any of those fields raises a structured `LegacyParakeetModelDeprecatedError` with a migration message. The legacy ONNX constants (e.g. `PARAKEET_TDT_ENCODER_INT8`, `PARAKEET_CTC_FP32`, `PARAKEET_SORTFORMER_FP32`) remain exported for one minor cycle for codemod migrations only and will be removed in a future release.
 </Callout>
 
 <Callout type="info">
 **On VAD:** when using `qvac-ext-lib-whisper.cpp`, you can optionally provide a separate model for voice activity detection (VAD); this is recommended. In turn, Parakeet handles VAD internally, so no additional model or configuration is required.
 </Callout>
 
+## Streaming with `transcribeStream()`
+
+`transcribeStream()` opens a duplex session for both engines — write audio chunks via `session.write(...)`, iterate events with `for await (const event of session) { ... }`. Events are typed as a discriminated union `{ type }`:
+
+- `{ type: "text", text }` — incremental transcript text.
+- `{ type: "segment", segment }` — segment metadata (whisper-only when `metadata: true`).
+- `{ type: "vad", speaking, probability }` — voice-activity-detection state (whisper-only).
+- `{ type: "endOfTurn", source: "whisper", silenceDurationMs }` — turn boundary detected from a measured silence window (whisper).
+- `{ type: "endOfTurn", source: "parakeet" }` — turn boundary detected from the EOU model's `<EOU>` token (parakeet; no silence window — the event is token-driven).
+
+The `source` field on `endOfTurn` lets consumers narrow the union: whisper events always carry a numeric `silenceDurationMs`; parakeet events never do.
+
+### Parakeet duplex streaming
+
+Pass `parakeetStreamingConfig` to `transcribeStream()` to override per-call streaming knobs (each falls back to its `parakeetConfig.streaming*` load-time counterpart):
+
+```ts
+const session = await transcribeStream({
+  modelId,
+  parakeetStreamingConfig: {
+    chunkMs: 1000,            // encoder cadence
+    historyMs: 30000,         // sortformer rolling-history window
+    leftContextMs: 500,       // ASR encoder left-context window
+    rightLookaheadMs: 200,    // ASR encoder right-lookahead window
+    emitPartials: true,       // emit partial segments before chunk boundaries
+    emitEnergyVad: false,     // CTC/TDT energy-based VAD hint (engine-internal)
+  },
+});
+
+for await (const event of session) {
+  switch (event.type) {
+    case "text":
+      process.stdout.write(event.text);
+      break;
+    case "endOfTurn":
+      // event.source: "whisper" | "parakeet"
+      console.log("\n[endOfTurn] turn boundary detected\n");
+      break;
+  }
+}
+```
+
+The synthetic `{ type: "endOfTurn", source: "parakeet" }` event surfaces whenever the EOU model emits an `<EOU>` token, and is the parakeet equivalent of whisper's silence-window EOU. Pair it with the `PARAKEET_EOU_120M_V1_Q8_0` checkpoint when you need explicit turn boundaries from parakeet.
+
 ## Examples
 
 ### `qvac-ext-lib-whisper.cpp`