feat(dictate): support configurable ASR backends

extensions/dictate/index.test.ts

@@ -195,10 +195,66 @@ function serviceFrame(
 test("registers main-editor shortcuts, cancel command, and shutdown cleanup", () => {
   const harness = createHarness();
   assert.deepEqual([...harness.shortcuts.keys()], ["alt+m", "alt+n"]);
-  assert.deepEqual([...harness.commands.keys()], ["dictate-cancel"]);
+  assert.deepEqual([...harness.commands.keys()], ["dictate-cancel", "dictate-status"]);
   assert.ok(harness.events.has("session_shutdown"));
 });
 
+test("status command negotiates a short read-only connection and reports backend diagnostics", async () => {
+  const harness = createHarness();
+  await harness.command("dictate-status")(
+    "",
+    harness.context as ExtensionCommandContext,
+  );
+  const socket = harness.sockets[0];
+  assert.ok(socket);
+  socket.connect();
+  const hello = harness.sentFrames(socket)[0];
+  assert.equal(hello?.type, "hello");
+  socket.frame({
+    version: PROTOCOL_VERSION,
+    type: "pong",
+    requestId: hello?.requestId,
+    backend: "openai",
+    model: "gpt-live-transcribe",
+  });
+  const ping = harness.sentFrames(socket)[1];
+  assert.equal(ping?.type, "ping");
+  socket.frame({
+    version: PROTOCOL_VERSION,
+    type: "pong",
+    requestId: ping?.requestId,
+  });
+
+  assert.deepEqual(harness.notifications, [
+    {
+      message: "Dictation backend: openai; model: gpt-live-transcribe",
+      type: "info",
+    },
+  ]);
+  assert.equal(socket.endCount, 1);
+});
+
+test("status diagnostics reject control characters without exposing them", async () => {
+  const harness = createHarness();
+  await harness.command("dictate-status")(
+    "",
+    harness.context as ExtensionCommandContext,
+  );
+  const socket = harness.sockets[0];
+  assert.ok(socket);
+  socket.connect();
+  const hello = harness.sentFrames(socket)[0];
+  socket.frame({
+    version: PROTOCOL_VERSION,
+    type: "pong",
+    requestId: hello?.requestId,
+    backend: "openai\nsecret",
+  });
+
+  assert.match(harness.notifications[0]?.message ?? "", /diagnostic backend is invalid/i);
+  assert.equal(socket.destroyCount, 1);
+});
+
 test("connection errors return to idle and the next start uses a fresh socket", async () => {
   const harness = createHarness();
   await harness.shortcut("alt+m")(harness.context);
@@ -277,7 +333,7 @@ test("renders authoritative service states and sends a bounded stop command", as
   serviceFrame(socket, generationId, "state", { state: "transcribing" });
 
   assert.deepEqual(harness.statuses, [
-    "loading model...",
+    "preparing transcription...",
     "● listening  ▁▁▁▁▁▁▁▁▁▁▁▁",
     "stopping...",
     "transcribing...",