fix: validate openai realtime transcription vad

extensions/openai/realtime-transcription-provider.test.ts

@@ -179,6 +179,24 @@ describe("buildOpenAIRealtimeTranscriptionProvider", () => {
     expect(resolved?.vadThreshold).toBe(0);
   });
 
+  it("drops malformed VAD timing settings", () => {
+    const provider = buildOpenAIRealtimeTranscriptionProvider();
+    const resolved = provider.resolveConfig?.({
+      cfg: {} as never,
+      rawConfig: {
+        providers: {
+          openai: {
+            silenceDurationMs: -1,
+            vadThreshold: 1.5,
+          },
+        },
+      },
+    });
+
+    expect(resolved?.silenceDurationMs).toBeUndefined();
+    expect(resolved?.vadThreshold).toBeUndefined();
+  });
+
   it("accepts the legacy openai-realtime alias", () => {
     const provider = buildOpenAIRealtimeTranscriptionProvider();
     expect(provider.aliases).toContain("openai-realtime");

extensions/openai/realtime-transcription-provider.ts

@@ -110,11 +110,27 @@ function normalizeProviderConfig(
     language: trimToUndefined(raw?.language),
     model: trimToUndefined(raw?.model) ?? trimToUndefined(raw?.sttModel),
     prompt: trimToUndefined(raw?.prompt),
-    silenceDurationMs: asFiniteNumber(raw?.silenceDurationMs),
-    vadThreshold: asFiniteNumber(raw?.vadThreshold),
+    silenceDurationMs: normalizeNonNegativeInteger(raw?.silenceDurationMs),
+    vadThreshold: normalizeVadThreshold(raw?.vadThreshold),
   };
 }
 
+function normalizeNonNegativeInteger(value: unknown): number | undefined {
+  const number = asFiniteNumber(value);
+  if (number === undefined || !Number.isSafeInteger(number) || number < 0) {
+    return undefined;
+  }
+  return number;
+}
+
+function normalizeVadThreshold(value: unknown): number | undefined {
+  const number = asFiniteNumber(value);
+  if (number === undefined || number < 0 || number > 1) {
+    return undefined;
+  }
+  return number;
+}
+
 function buildOpenAIRealtimeTranscriptionSessionCreateConfig(
   config: OpenAIRealtimeTranscriptionSessionConfig,
 ): OpenAIRealtimeTranscriptionSessionCreate {