Merge feat/parakeet-engine: Parakeet TDT 0.6B v3 English engine (spec 001 workstream 7)

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

# Conflicts:
#	AGENTS.md
#	bun.lock
#	docs/Decisions.md
#	src/lib/models.ts
#	src/worker/inference.worker.ts
#	src/worker/protocol.ts
#	tests/models.test.ts

tests/models.test.ts

@@ -10,6 +10,8 @@ import {
   formatModelSize,
   getFasterWhisperModel,
   getModel,
+  modelFamily,
+  PARAKEET_MODEL_ID,
   resolveDefaultDtype,
   taskForModel,
 } from "../src/lib/models";
@@ -21,6 +23,8 @@ function stripRepoDecorations(id: string): string {
   return id.replace(/(_timestamped|-ONNX)$/, "");
 }
 
+const WHISPER_MODELS = MODELS.filter((model) => modelFamily(model) === "whisper");
+
 describe("MODELS catalog", () => {
   test("contains the curated D-006 lineup from the onnx-community org", () => {
     const ids = MODELS.map((model) => model.id);
@@ -35,12 +39,15 @@ describe("MODELS catalog", () => {
       "onnx-community/whisper-medium-ONNX",
       "onnx-community/whisper-large-v3-turbo",
       `${DANISH_MODELS_HF_OWNER}/whisper-small-danish-ONNX`,
+      // Not Whisper: the D-WS7a Parakeet engine path, last so it never
+      // becomes anyone's accidental default.
+      "ysdede/parakeet-tdt-0.6b-v3-onnx",
     ]);
     expect(new Set(ids).size).toBe(ids.length);
   });
 
   test(".en variants are English-only; the rest are multilingual", () => {
-    for (const model of MODELS) {
+    for (const model of WHISPER_MODELS) {
       // Hub repo names may carry decorations (e.g. "_timestamped", "-ONNX")
       // after the size suffix — judge English-ness on the undecorated name.
       expect(model.multilingual).toBe(!stripRepoDecorations(model.id).endsWith(".en"));
@@ -72,10 +79,10 @@ describe("MODELS catalog", () => {
     expect(getModel("onnx-community/whisper-nonexistent")).toBeUndefined();
   });
 
-  test("every model maps to a faster-whisper name for the server engine (D-013)", () => {
+  test("every Whisper model maps to a faster-whisper name for the server engine (D-013)", () => {
     // The Danish conversions (D-WS6a) have no faster-whisper alias; their
     // server-engine name is a Hub repo id — covered by the Danish suite below.
-    for (const model of MODELS.filter((m) => !m.id.startsWith(`${DANISH_MODELS_HF_OWNER}/`))) {
+    for (const model of WHISPER_MODELS.filter((m) => !m.id.startsWith(`${DANISH_MODELS_HF_OWNER}/`))) {
       // The onnx-community ids and faster-whisper's aliases share the same
       // size suffix ("tiny.en", …, "large-v3-turbo") once repo-name
       // decorations ("_timestamped", "-ONNX") are stripped; keeping them
@@ -298,3 +305,41 @@ describe("taskForModel (D-WS4a)", () => {
     expect(taskForModel("someone/unknown", "translate")).toBe("transcribe");
   });
 });
+
+describe("Parakeet catalog entry (D-WS7a)", () => {
+  const parakeet = getModel(PARAKEET_MODEL_ID)!;
+
+  test("family defaults to whisper when absent", () => {
+    expect(modelFamily(getModel(DEFAULT_MODEL_ID))).toBe("whisper");
+    expect(modelFamily(undefined)).toBe("whisper");
+    expect(modelFamily(parakeet)).toBe("parakeet");
+  });
+
+  test("is English-only and browser-only (no faster-whisper name)", () => {
+    expect(parakeet.multilingual).toBe(false);
+    expect(parakeet.fasterWhisperModel).toBeUndefined();
+    expect(getFasterWhisperModel(PARAKEET_MODEL_ID)).toBeUndefined();
+  });
+
+  test("WASM runs int8 for both parts; WebGPU is fp16 encoder + int8 decoder", () => {
+    expect(resolveDefaultDtype(PARAKEET_MODEL_ID, "wasm")).toBe("q8");
+    expect(resolveDefaultDtype(PARAKEET_MODEL_ID, "webgpu")).toEqual({
+      encoder_model: "fp16",
+      decoder_model_merged: "q8",
+    });
+  });
+
+  test("download size is the real file sizes, not a parameter estimate", () => {
+    expect(estimateDefaultDownloadBytes(parakeet, "wasm")).toBe(
+      652_183_999 + 18_202_004 + 102_132,
+    );
+    expect(estimateDefaultDownloadBytes(parakeet, "webgpu")).toBe(
+      1_238_960_452 + 18_202_004 + 102_132,
+    );
+    expect(formatModelSize(estimateDefaultDownloadBytes(parakeet, "wasm"))).toBe("670 MB");
+  });
+
+  test("peak load memory is twice the larger weight file", () => {
+    expect(estimatePeakLoadBytes(parakeet, "q8")).toBe(2 * 652_183_999);
+  });
+});