feat: further kernel power and power optimizations

kernel/src/Timekeeping/ApicTimer.hpp

@@ -32,6 +32,11 @@ namespace Timekeeping {
     // one-shot LAPIC timer while idle; APs keep their existing simple wait.
     void IdleOnce(bool hasMwait, volatile uint64_t* monitorAddr = nullptr);
 
+    // Mark recent latency-sensitive input activity. Idle policy uses this to
+    // stay in shallow, high-responsiveness mode briefly while the user is
+    // moving the pointer or dragging windows.
+    void NoteInteractiveActivity(uint32_t durationMs = 250);
+
     // Busy-wait sleep for the given number of milliseconds
     void Sleep(uint64_t ms);
 };