TTS: adopt runtime backend catalog

src/extension-host/runtime-backend-catalog.test.ts

@@ -102,6 +102,11 @@ describe("runtime-backend-catalog", () => {
     expect(entries.find((entry) => entry.backendId === "edge")?.capabilities).toEqual([
       "tts.synthesis",
     ]);
+    expect(catalog.listExtensionHostTtsRuntimeBackendIds()).toEqual([
+      "openai",
+      "elevenlabs",
+      "edge",
+    ]);
   });
 
   it("aggregates runtime-backend catalog entries across subsystem families", async () => {

src/extension-host/runtime-backend-catalog.ts

@@ -1,3 +1,4 @@
+import type { TtsProvider } from "../config/types.tts.js";
 import type { MediaUnderstandingCapability } from "../media-understanding/types.js";
 import { EXTENSION_HOST_REMOTE_EMBEDDING_PROVIDER_IDS } from "./embedding-runtime-registry.js";
 import type { EmbeddingProviderId } from "./embedding-runtime-types.js";
@@ -121,6 +122,12 @@ export function listExtensionHostTtsRuntimeBackendCatalogEntries(): readonly Ext
   }));
 }
 
+export function listExtensionHostTtsRuntimeBackendIds(): readonly TtsProvider[] {
+  return listExtensionHostTtsRuntimeBackendCatalogEntries().map(
+    (entry) => entry.backendId as TtsProvider,
+  );
+}
+
 export function listExtensionHostRuntimeBackendCatalogEntries(): readonly ExtensionHostRuntimeBackendCatalogEntry[] {
   return [
     ...listExtensionHostEmbeddingRuntimeBackendCatalogEntries(),

src/extension-host/tts-runtime-setup.test.ts

@@ -1,7 +1,7 @@
 import { mkdtempSync, rmSync, writeFileSync } from "node:fs";
 import os from "node:os";
 import path from "node:path";
-import { afterEach, describe, expect, it } from "vitest";
+import { afterEach, describe, expect, it, vi } from "vitest";
 import { withEnv } from "../test-utils/env.js";
 import type { ResolvedTtsConfig } from "./tts-config.js";
 import {
@@ -9,6 +9,10 @@ import {
   resolveExtensionHostTtsRequestSetup,
 } from "./tts-runtime-setup.js";
 
+vi.mock("./runtime-backend-catalog.js", () => ({
+  listExtensionHostTtsRuntimeBackendIds: vi.fn(() => ["openai", "elevenlabs", "edge"]),
+}));
+
 const tempDirs: string[] = [];
 
 function createPrefsPath(contents: object): string {

src/extension-host/tts-runtime-setup.ts

@@ -1,10 +1,8 @@
 import { existsSync, readFileSync } from "node:fs";
 import type { TtsProvider } from "../config/types.tts.js";
+import { listExtensionHostTtsRuntimeBackendIds } from "./runtime-backend-catalog.js";
 import type { ResolvedTtsConfig } from "./tts-config.js";
-import {
-  resolveExtensionHostTtsApiKey,
-  resolveExtensionHostTtsProviderOrder,
-} from "./tts-runtime-registry.js";
+import { resolveExtensionHostTtsApiKey } from "./tts-runtime-registry.js";
 
 type TtsUserPrefs = {
   tts?: {
@@ -67,8 +65,9 @@ export function resolveExtensionHostTtsRequestSetup(params: {
 
   const provider =
     params.providerOverride ?? resolveExtensionHostTtsProvider(params.config, params.prefsPath);
+  const providerOrder = listExtensionHostTtsRuntimeBackendIds();
   return {
     config: params.config,
-    providers: resolveExtensionHostTtsProviderOrder(provider),
+    providers: [provider, ...providerOrder.filter((candidate) => candidate !== provider)],
   };
 }

src/extension-host/tts-status.test.ts

@@ -1,10 +1,14 @@
-import { describe, expect, it } from "vitest";
+import { describe, expect, it, vi } from "vitest";
 import {
   formatExtensionHostTtsStatusText,
   resolveExtensionHostTtsStatusSnapshot,
   setExtensionHostLastTtsAttempt,
 } from "./tts-status.js";
 
+vi.mock("./runtime-backend-catalog.js", () => ({
+  listExtensionHostTtsRuntimeBackendIds: vi.fn(() => ["openai", "elevenlabs", "edge"]),
+}));
+
 describe("tts-status", () => {
   it("builds a status snapshot from host-owned preferences and runtime state", () => {
     const config = {

src/extension-host/tts-status.ts

@@ -1,4 +1,5 @@
 import type { TtsProvider } from "../config/types.tts.js";
+import { listExtensionHostTtsRuntimeBackendIds } from "./runtime-backend-catalog.js";
 import type { ResolvedTtsConfig } from "./tts-config.js";
 import {
   getExtensionHostTtsMaxLength,
@@ -9,7 +10,6 @@ import {
 import {
   isExtensionHostTtsProviderConfigured,
   resolveExtensionHostTtsApiKey,
-  resolveExtensionHostTtsProviderOrder,
 } from "./tts-runtime-registry.js";
 import { resolveExtensionHostTtsProvider } from "./tts-runtime-setup.js";
 
@@ -57,8 +57,8 @@ export function resolveExtensionHostTtsStatusSnapshot(params: {
 }): ExtensionHostTtsStatusSnapshot {
   const { config, prefsPath } = params;
   const provider = resolveExtensionHostTtsProvider(config, prefsPath);
-  const fallbackProviders = resolveExtensionHostTtsProviderOrder(provider)
-    .slice(1)
+  const fallbackProviders = listExtensionHostTtsRuntimeBackendIds()
+    .filter((candidate) => candidate !== provider)
     .filter((candidate) => isExtensionHostTtsProviderConfigured(config, candidate));
   return {
     enabled: isExtensionHostTtsEnabled(config, prefsPath),