Fix: Close button now properly exits the application

- window:close IPC now sets isAppQuitting flag before closing
- Application closes completely instead of hiding to tray
- Built portable release: IP Monitor-Portable-1.0.0.exe (78MB)

build-output/win-unpacked/portable.txt

@@ -1 +0,0 @@
-Portable Mode

src/main/index.ts

@@ -211,7 +211,11 @@ function setupIpcHandlers() {
       mainWindow?.maximize()
     }
   })
-  ipcMain.on('window:close', () => mainWindow?.close())
+  ipcMain.on('window:close', () => {
+    // Çarpı butonuna basınca uygulamayı tamamen kapat
+    isAppQuitting = true
+    mainWindow?.close()
+  })
 
   // IP Service
   ipcMain.handle(IPC_CHANNELS.GET_IP_INFO, async () => {