Add improvements 2

gateway/app/routes/demo.py

@@ -8,6 +8,7 @@ import httpx
 import structlog
 
 from app.core.config import settings
+from app.core.header_manager import header_manager
 
 logger = structlog.get_logger()
 
@@ -29,12 +30,8 @@ async def proxy_demo_service(path: str, request: Request):
     if request.method in ["POST", "PUT", "PATCH"]:
         body = await request.body()
 
-    # Forward headers (excluding host)
-    headers = {
-        key: value
-        for key, value in request.headers.items()
-        if key.lower() not in ["host", "content-length"]
-    }
+    # Use unified HeaderManager for consistent header forwarding
+    headers = header_manager.get_all_headers_for_proxy(request)
 
     try:
         async with httpx.AsyncClient(timeout=30.0) as client: