fix(handlers): bypass box creation limits for batched uploads

Update `createOrAppendBox` to accept the upload policy and admin status, allowing policy enforcement to be handled during the box creation/append decision process. This ensures that appending files to an existing batch does not incorrectly trigger daily or active box creation limits, as no new box is being created.

Also, add unit tests to verify that batched uploads successfully bypass both daily and active box creation caps.

backend/libs/middleware/bans_test.go

@@ -79,6 +79,26 @@ func TestBansMiddlewareAutoBansMaliciousPaths(t *testing.T) {
 	}
 }
 
+func TestBansMiddlewareSkipsAutoBanWhenDisabled(t *testing.T) {
+	bans := newMiddlewareBanService(t)
+	handler := Chain(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		http.NotFound(w, r)
+	}), Bans(slog.New(slog.NewTextHandler(io.Discard, nil)), bans, nil))
+
+	for i := 0; i < 5; i++ {
+		request := httptest.NewRequest(http.MethodGet, "/.env", nil)
+		request.RemoteAddr = "203.0.113.23:6070"
+		response := httptest.NewRecorder()
+		handler.ServeHTTP(response, request)
+		if response.Code == http.StatusForbidden {
+			t.Fatalf("request %d was blocked while auto-ban disabled", i+1)
+		}
+	}
+	if _, ok, err := bans.Match("203.0.113.23", time.Now().UTC()); err != nil || ok {
+		t.Fatalf("disabled auto-ban Match = %v, %v", ok, err)
+	}
+}
+
 func newMiddlewareBanService(t *testing.T) *services.BanService {
 	t.Helper()
 	root := t.TempDir()