feat(model): Top5#1 结构化流事件 + WS 事件体系（对齐 OpenClaw AssistantMessageEvent）

- 新增 model/stream.go：StreamKind(text/thinking/tool_call 各 start/delta/end + tool_execution)
  + StreamEvent{Kind,Delta,Index,ID}。
- ChatStream 签名 onChunk func(delta string)→onEvent func(StreamEvent)；loop OnStream 同改；
  streamStep 转发结构化事件。
- openai：text_delta + text_start/text_end（正文三段式）；anthropic：文本块 text_*/tool_call_*
  按块 Index（content_block_stop 分支）真分段；fallback：有事件即交付。
- ws_hub：wsEvent 壳补 turnId/seq；新增 broadcastStream；streamChat 每帧打 turnId+seq；
  stream.go 把事件 publish 到 bus ws.stream。
- ws_bridge：streamEventData 映射 text_*→message.start/delta/end、thinking_*→thinking.*、
  tool_call_*→tool_call.*、tool_execution_update→tool_execution.update，未知回退 stream_chunk。
- 前端 ws.ts：解析 message.start/delta/end、thinking.start/delta/end(pendingThinking)、
  tool_call.start/end→addTool、tool_execution.update；保留旧 stream_chunk/thinking/tool_used 兼容；
  types.ts 补 turnId/seq。Docs/api-client.md 增 §3.1 v0.4。

已知限制（注释/文档标注）：turnId 在 OnStream→bus→relay 路径暂为空（StreamEvent 无 turnId 字段，
bus ws.stream 载荷不带 turn）；OpenAI adapter 未解析 tool_call 段；thinking 段两 adapter 暂不发；
tool_execution.update 是保留项（随工具循环钩子后置）。go build/vet/test + 前端 tsc 全绿。

cmd/cyrene/stream.go

@@ -1,22 +1,31 @@
 package main
 
-import "context"
+import (
+	"context"
 
-// streamChunkSubject is the bus subject the loop's OnStream closure publishes
-// each token delta to. The gateway hub subscribes to ws.> and re-broadcasts it
-// as a ws.stream_chunk frame to every client.
-const streamChunkSubject = "ws.stream_chunk"
+	"git.yeij.top/AskaEth/Cyrene_v2/internal/runtime/model"
+)
 
-// streamChunk is the loop's OnStream callback. It publishes one token delta to
-// the gateway's streaming subject so the hub fans it out to every client as a
-// ws.stream_chunk frame. It is a no-op when no bus is wired and never blocks the
-// loop: bus.Publish is asynchronous and a full per-subscription buffer drops the
-// event rather than stalling the model stream.
-func (a *app) streamChunk(delta string) {
+// streamSubject is the bus subject the loop's OnStream closure publishes each
+// structured stream event to. The gateway hub subscribes to ws.> and carries a
+// dedicated branch for this subject that maps the model.StreamEvent to the typed
+// downstream WS event (message.*/thinking.*/tool_call.*) with a seq number.
+//
+// It MUST stay in sync with wsStreamSubject in internal/services/gateway/ws_hub.go;
+// the two packages cannot share a const without pulling the gateway into the
+// main binary's import graph, so the literal is duplicated and documented.
+const streamSubject = "ws.stream"
+
+// streamChunk is the loop's OnStream callback. It publishes one structured
+// stream event to the gateway's streaming subject so the hub fans it out to
+// every client as the matching typed WS event. It is a no-op when no bus is
+// wired and never blocks the loop: bus.Publish is asynchronous and a full
+// per-subscription buffer drops the event rather than stalling the model stream.
+func (a *app) streamChunk(ev model.StreamEvent) {
 	if a.bus == nil {
 		return
 	}
-	if err := a.bus.Publish(context.Background(), streamChunkSubject, map[string]any{"delta": delta}); err != nil {
-		a.log.Warn("stream chunk publish", "err", err)
+	if err := a.bus.Publish(context.Background(), streamSubject, ev); err != nil {
+		a.log.Warn("stream event publish", "err", err)
 	}
 }