feat(voice): WebSocket 端点 + 客户端↔网关协议(Phase 1 地基)

加 gorilla/websocket(无 genproto 冲突)。voice/protocol.go 定死单条 WS 的消息协议:
二进制帧=音频(上行麦克风/下行TTS),文本帧=JSON 控制/事件(ClientMsg:start/end/barge_in/
bye;ServerMsg:ready/transcript/task/speaking/tts_end/error);音频 PCM 16k 单声道。
handler/voice.go: GET /api/v1/voice/stream 升级 WS,鉴权走 AuthFromHeaderOrQuery(?token=,
WS 带不了 Bearer),会话外壳 + 协议读循环(音频帧/控制消息分派)已通,火山 ASR/TTS 客户端
在下一步挂 onAudio/onControl 的 TODO 点接入。build+vet+test 绿。

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

sundynix-gateway/go.sum

@@ -63,6 +63,8 @@ github.com/google/pprof v0.0.0-20221118152302-e6195bd50e26 h1:Xim43kblpZXfIBQsbu
 github.com/google/pprof v0.0.0-20221118152302-e6195bd50e26/go.mod h1:dDKJzRmX4S37WGHujM7tX//fmj1uioxKzKxz3lo4HJo=
 github.com/google/uuid v1.6.0 h1:NIvaJDMOsjHA8n1jAhLSgzrAzy1Hgr+hNrb57e+94F0=
 github.com/google/uuid v1.6.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
+github.com/gorilla/websocket v1.5.3 h1:saDtZ6Pbx/0u+bgYQ3q96pZgCzfhKXGPqt7kZ72aNNg=
+github.com/gorilla/websocket v1.5.3/go.mod h1:YR8l580nyteQvAITg2hZ9XVh4b55+EU/adAjf1fMHhE=
 github.com/grpc-ecosystem/grpc-gateway/v2 v2.29.0 h1:5VipnvEpbqr2gA2VbM+nYVbkIF28c5ZQfqCBQ5g2xfk=
 github.com/grpc-ecosystem/grpc-gateway/v2 v2.29.0/go.mod h1:Hyl3n6Twe1hvtd9XUXDec4pTvgMSEixRuQKPTMH2bNs=
 github.com/jackc/pgpassfile v1.0.0 h1:/6Hmqy13Ss2zCq62VdNG8tM1wchn8zjSGOBJ6icpsIM=