fix: Resolve array comparison error and add inference stop functionality

- Fix ambiguous truth value error in InferencePipeline result handling
- Add stop inference button to deployment dialog with proper UI state management
- Improve error handling for tuple vs dict result types

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

cluster4npu_ui/core/functions/InferencePipeline.py

@@ -215,8 +215,14 @@ class PipelineStage:
             timeout_start = time.time()
             while time.time() - timeout_start < 5.0:  # 5 second timeout
                 result = self.multidongle.get_latest_inference_result(timeout=0.1)
-                # Check if result is not None and not an empty dict
+                # Check if result is not None and not an empty dict/tuple
-                if result is not None and (not isinstance(result, dict) or result):
+                if result is not None:
+                    if isinstance(result, dict):
+                        if result:  # Non-empty dict
+                            inference_result = result
+                            break
+                    else:
+                        # For tuple results like (probability, result_string)
                         inference_result = result
                         break
                 time.sleep(0.01)

cluster4npu_ui/ui/dialogs/deployment.py

@@ -220,6 +220,12 @@ class DeploymentDialog(QDialog):
         self.deploy_button.setEnabled(False)
         button_layout.addWidget(self.deploy_button)
         
+        self.stop_button = QPushButton("Stop Inference")
+        self.stop_button.clicked.connect(self.stop_deployment)
+        self.stop_button.setEnabled(False)
+        self.stop_button.setVisible(False)
+        button_layout.addWidget(self.stop_button)
+        
         button_layout.addStretch()
         
         self.close_button = QPushButton("Close")
@@ -518,6 +524,29 @@ Stage Configurations:
         
         self.deployment_worker.start()
     
+    def stop_deployment(self):
+        """Stop the current deployment/inference."""
+        if self.deployment_worker and self.deployment_worker.isRunning():
+            reply = QMessageBox.question(self, "Stop Inference",
+                                       "Are you sure you want to stop the inference?",
+                                       QMessageBox.Yes | QMessageBox.No)
+            if reply == QMessageBox.Yes:
+                self.deployment_log.append("Stopping inference...")
+                self.status_label.setText("Stopping inference...")
+                self.deployment_worker.stop()
+                self.deployment_worker.wait(3000)  # Wait up to 3 seconds
+                
+                # Update UI
+                self.stop_button.setEnabled(False)
+                self.stop_button.setVisible(False)
+                self.deploy_button.setEnabled(True)
+                self.close_button.setText("Close")
+                self.progress_bar.setVisible(False)
+                
+                self.deployment_log.append("Inference stopped.")
+                self.status_label.setText("Inference stopped")
+                self.dongle_status.setText("Pipeline stopped")
+    
     def update_progress(self, value: int, message: str):
         """Update deployment progress."""
         self.progress_bar.setValue(value)
@@ -537,6 +566,11 @@ Stage Configurations:
         self.deployment_log.append("Connecting to dongles...")
         self.dongle_status.setText("Initializing dongles...")
         
+        # Show stop button and hide deploy button
+        self.stop_button.setEnabled(True)
+        self.stop_button.setVisible(True)
+        self.deploy_button.setEnabled(False)
+    
     def on_deployment_completed(self, success: bool, message: str):
         """Handle deployment completion."""
         self.progress_bar.setValue(100)
@@ -545,12 +579,18 @@ Stage Configurations:
             self.deployment_log.append(f"SUCCESS: {message}")
             self.status_label.setText("Deployment completed successfully!")
             self.dongle_status.setText("Pipeline running on dongles")
+            # Keep stop button visible for successful deployment
+            self.stop_button.setEnabled(True)
+            self.stop_button.setVisible(True)
             QMessageBox.information(self, "Deployment Success", message)
         else:
             self.deployment_log.append(f"FAILED: {message}")
             self.status_label.setText("Deployment failed")
-            
+            # Hide stop button for failed deployment
+            self.stop_button.setEnabled(False)
+            self.stop_button.setVisible(False)
             self.deploy_button.setEnabled(True)
+            
         self.close_button.setText("Close")
         self.progress_bar.setVisible(False)
     
@@ -560,6 +600,9 @@ Stage Configurations:
         self.status_label.setText("Deployment failed")
         QMessageBox.critical(self, "Deployment Error", error)
         
+        # Hide stop button and show deploy button on error
+        self.stop_button.setEnabled(False)
+        self.stop_button.setVisible(False)
         self.deploy_button.setEnabled(True)
         self.close_button.setText("Close")
         self.progress_bar.setVisible(False)