feat: A2DP bluetooth audio working

kernel/src/Drivers/USB/Bluetooth/Bluetooth.hpp

@@ -19,6 +19,14 @@ namespace Drivers::USB::Bluetooth {
     // once the boot filesystems are up; a no-op if nothing is pending.
     void ServiceDeferredInit();
 
+    // Steady-state event service: drains the xHCI event ring + Bluetooth ACL
+    // RX ring and flushes queued HCI replies.  Called from the idle loop so
+    // inbound traffic (the headset's SDP/AVRCP queries, AVDTP commands, ACL
+    // credits) is processed even when no syscall happens to be pumping a BT
+    // wait loop.  Cheap no-op when the adapter is down; safe from any core
+    // (PollEvents/DrainEvents/ProcessPendingCommands all self-serialize).
+    void ServiceEvents();
+
     // Query adapter state
     bool IsInitialized();
     uint8_t GetSlotId();