debug: trace controller input packets

Log decoded GIP commands and standard input reports after wireless pairing
to isolate missing input delivery without changing protocol behavior.

Co-Authored-By: openai/gpt-5.6-luna: added input path diagnostics

src/app/api.cpp

@@ -216,6 +216,10 @@ auto controller_listener::on_input(
         ~xone::load_le16(data.data() + 12));
     ++controller_.input_sequence;
     controller_.input_active = true;
+    xone::log_msg(xone::log_level::debug,
+                  "api: input wcid=%d buttons=0x%04x lt=%d rt=%d",
+                  controller_.wcid, controller_.buttons,
+                  controller_.trigger_left, controller_.trigger_right);
 }
 
 auto xone_dongle::setup_controller(controller& c) -> void
@@ -343,6 +347,15 @@ auto xone_dongle::handle_qos_data(
     if (!found || !found->gip_adapter)
         return;
 
+    if (payload.size() >= 4) {
+        auto packet_length = static_cast<std::uint8_t>(payload[3] & 0x7f);
+        xone::log_msg(xone::log_level::debug,
+                      "api: GIP rx wcid=%d cmd=0x%02x opts=0x%02x "
+                      "seq=0x%02x len=%d",
+                      wcid, payload[0], payload[1], payload[2],
+                      packet_length);
+    }
+
     if (auto err = found->gip_adapter->process_buffer(payload); err != 0)
         xone::log_msg(xone::log_level::debug,
                       "api: GIP packet processing failed (%d)", err);