Feature: Add power management to keep macOS client always responsive

macos/main.mm

@@ -6,6 +6,7 @@
 #import <signal.h>
 #import <unistd.h>
 #import <IOKit/IOKitLib.h>
+#import <IOKit/pwr_mgt/IOPMLib.h>
 #import <fstream>
 #import <thread>
 #import <atomic>
@@ -478,6 +479,30 @@ int main(int argc, const char* argv[])
     @autoreleasepool {
         NSLog(@"=== macOS Ghost Client ===");
 
+        // ============== Power Management: Keep System Awake ==============
+        // 1. Disable App Nap - prevent macOS from suspending this process
+        id<NSObject> powerActivity = [[NSProcessInfo processInfo]
+            beginActivityWithOptions:(NSActivityUserInitiated | NSActivityIdleSystemSleepDisabled)
+            reason:@"Remote control client must maintain persistent connection"];
+        NSLog(@"App Nap disabled, activity token acquired");
+
+        // 2. Prevent system idle sleep using IOKit power assertion
+        IOPMAssertionID sleepAssertionID = 0;
+        IOReturn result = IOPMAssertionCreateWithName(
+            kIOPMAssertionTypeNoIdleSleep,
+            kIOPMAssertionLevelOn,
+            CFSTR("SimpleRemoter macOS client - maintaining remote connection"),
+            &sleepAssertionID
+        );
+        if (result == kIOReturnSuccess) {
+            NSLog(@"Power assertion created: system idle sleep disabled (ID: %u)", sleepAssertionID);
+        } else {
+            NSLog(@"Warning: Failed to create power assertion (error: 0x%x)", result);
+        }
+
+        // 3. Display sleep: managed by ScreenHandler - only prevents display sleep
+        //    when remote desktop is actively connected (saves power when idle)
+
         // Setup signal handlers
         setupSignals();
 
@@ -549,6 +574,15 @@ int main(int argc, const char* argv[])
         }
 
         NSLog(@"Shutting down...");
+
+        // Release power assertions
+        if (sleepAssertionID) {
+            IOPMAssertionRelease(sleepAssertionID);
+            NSLog(@"Released sleep assertion");
+        }
+        // Display assertion is managed by ScreenHandler (released in stop())
+        // powerActivity is automatically released when exiting @autoreleasepool
+        (void)powerActivity;  // Suppress unused variable warning
     }
 
     return 0;