fix(voice): 浏览器语音默认走服务端 ASR

Web Speech 依赖 Google，国内浏览器常无法转文字；支持麦克风时改为录音后走自有 ASR，并补全网络异常时的降级匹配。

Co-authored-by: Cursor <cursoragent@cursor.com>

src/hooks/useVoiceSession.ts

@@ -1,10 +1,10 @@
 import { useCallback, useEffect, useRef, useState } from 'react';
 import { transcribeOneShot } from '../voice/asrTransport';
 import { mapMicError } from '../voice/audioAnalyser';
-import { shouldFallbackToServerAsr, shouldPreferServerAsr } from '../voice/capabilities';
+import { shouldFallbackToServerAsr, shouldUseLiveSpeech } from '../voice/capabilities';
 import { MicCapture } from '../voice/micCapture';
 import { waitForMicRelease } from '../voice/micSession';
-import { createLiveSpeechRecognition, isSpeechRecognitionSupported } from '../voice/speechRecognition';
+import { createLiveSpeechRecognition } from '../voice/speechRecognition';
 import type { VoiceSessionPhase } from '../voice/types';
 
 const MIN_RECORD_MS = 500;
@@ -19,9 +19,7 @@ export function useVoiceSession({
   const [phase, setPhase] = useState<VoiceSessionPhase>('idle');
   const [text, setText] = useState('');
   const [analyser, setAnalyser] = useState<AnalyserNode | null>(null);
-  const [liveRecognition, setLiveRecognition] = useState(
-    isSpeechRecognitionSupported() && !shouldPreferServerAsr(),
-  );
+  const [liveRecognition, setLiveRecognition] = useState(shouldUseLiveSpeech());
 
   const committedRef = useRef('');
   const interimRef = useRef('');
@@ -155,7 +153,7 @@ export function useVoiceSession({
         if (sessionRef.current !== sessionId) return;
 
         startedAtRef.current = Date.now();
-        const useLiveSpeech = isSpeechRecognitionSupported() && !shouldPreferServerAsr();
+        const useLiveSpeech = shouldUseLiveSpeech();
 
         if (useLiveSpeech) {
           const recognition = createLiveSpeechRecognition({