Fix StreamCancelFn type definition

StreamCancelFn was incorrectly defined as func() but is actually used as func(context.Context) error throughout the codebase.

This caused build failures in multiple places:

- wshclientutil.go:66: cannot use func(ctx context.Context) error as func() value

- web.go:255: cannot use func() as func(context.Context) error value

Fixed by correcting the type definition in wshrpctypes.go to match actual usage.

Fixes build errors introduced in #2709

Author: stevenvo

pkg/wshrpc/wshclient/wshclientutil.go

@@ -63,8 +63,8 @@ func sendRpcRequestResponseStreamHelper[T any](w *wshutil.WshRpc, command string
 		rtnErr(respChan, err)
 		return respChan
 	}
-	opts.StreamCancelFn = func(ctx context.Context) error {
-		return reqHandler.SendCancel(ctx)
+	opts.StreamCancelFn = func() {
+		reqHandler.SendCancel(context.Background())
 	}
 	go func() {
 		defer func() {

pkg/wshrpc/wshrpctypes.go

@@ -373,7 +373,7 @@ type RpcOpts struct {
 	NoResponse bool   `json:"noresponse,omitempty"`
 	Route      string `json:"route,omitempty"`
 
-	StreamCancelFn func() `json:"-"` // this is an *output* parameter, set by the handler
+	StreamCancelFn func(context.Context) error `json:"-"` // this is an *output* parameter, set by the handler
 }
 
 const (