SSE en formato Claude Code CLI via ?format=claude

Nuevo ClaudeFormatEmitter traduce eventos nativos al formato exacto
que produce Claude Code CLI: content_block_start/delta/stop, tool_result,
assistant snapshots, result con usage/cost, done.

- streaming/claude_format.py: ClaudeFormatEmitter + DualEmitter
- base.py: enriquecer eventos con tool_call_id, raw_output, tool_arguments
- engine.py: usage/cost en EXECUTION_COMPLETED
- routes.py: ?format=claude en /sessions/{id}/stream
- main.py: DualEmitter wiring (emite a ambos formatos)

El frontend puede consumir el stream sin cambios — mismos event types
que Claude Code CLI. El formato nativo sigue disponible para el dashboard.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/api/routes.py

@@ -68,13 +68,15 @@ def set_dependencies(
     context_engine: Any,
     memory_store: Any,
     sse_emitter: Any,
-    mcp_registry: Any,
+    claude_emitter: Any = None,
+    mcp_registry: Any = None,
 ) -> None:
     _deps["storage"] = storage
     _deps["model_adapter"] = model_adapter
     _deps["context_engine"] = context_engine
     _deps["memory_store"] = memory_store
     _deps["sse"] = sse_emitter
+    _deps["claude_sse"] = claude_emitter
     _deps["mcp_registry"] = mcp_registry
 
 
@@ -207,22 +209,33 @@ async def _execute_and_persist(orchestrator, storage, session, message) -> dict[
 # ------------------------------------------------------------------
 
 @router.get("/sessions/{session_id}/stream")
-async def stream_session(session_id: str) -> StreamingResponse:
+async def stream_session(session_id: str, format: str = "native") -> StreamingResponse:
     storage = _get_storage()
     session = await storage.get_session(session_id)
     if not session:
         raise HTTPException(status_code=404, detail="Session not found")
 
-    sse = _get_sse()
+    headers = {
+        "Cache-Control": "no-cache",
+        "Connection": "keep-alive",
+        "X-Accel-Buffering": "no",
+    }
 
+    if format == "claude":
+        claude_sse = _deps.get("claude_sse")
+        if not claude_sse:
+            raise HTTPException(status_code=501, detail="Claude format emitter not available")
+        return StreamingResponse(
+            claude_sse.subscribe(session_id),
+            media_type="text/event-stream",
+            headers=headers,
+        )
+
+    sse = _get_sse()
     return StreamingResponse(
         sse.subscribe(session_id),
         media_type="text/event-stream",
-        headers={
-            "Cache-Control": "no-cache",
-            "Connection": "keep-alive",
-            "X-Accel-Buffering": "no",
-        },
+        headers=headers,
     )