Fix printer detection, implement portable deployment with SumatraPDF

- Fixed network printer enumeration (PRINTER_ENUM_LOCAL | PRINTER_ENUM_CONNECTIONS)
- Added printer name truncation to 20 chars with full name mapping
- Implemented silent PDF printing using SumatraPDF with landscape orientation
- Added auto-dismiss for success popup (3 seconds)
- Bundled SumatraPDF inside executable for portable single-file deployment
- Updated build script to embed SumatraPDF
- Added setup_sumatra.ps1 for downloading SumatraPDF portable
- Added DEPLOYMENT.md documentation

label_printer_gui.py

@@ -393,7 +393,7 @@ class LabelPrinterApp(App):
                     
                     # Use Clock.schedule_once to update UI from main thread
                     Clock.schedule_once(lambda dt: popup.dismiss(), 0)
-                    Clock.schedule_once(lambda dt: self.show_popup("Success", "Label printed successfully!"), 0.1)
+                    Clock.schedule_once(lambda dt: self.show_popup("Success", "Label printed successfully!", auto_dismiss=True), 0.1)
                     # Clear inputs after successful print (but keep printer selection)
                     Clock.schedule_once(lambda dt: self.clear_inputs(), 0.2)
                 else:
@@ -420,8 +420,14 @@ class LabelPrinterApp(App):
         self.cable_id_input.text = ''
         # Printer selection is NOT cleared - it persists until user changes it
     
-    def show_popup(self, title, message):
-        """Show a popup message"""
+    def show_popup(self, title, message, auto_dismiss=False):
+        """Show a popup message
+        
+        Args:
+            title (str): Popup title
+            message (str): Popup message
+            auto_dismiss (bool): If True, popup will auto-dismiss after 3 seconds
+        """
         popup = Popup(
             title=title,
             content=BoxLayout(
@@ -439,6 +445,10 @@ class LabelPrinterApp(App):
         popup.content.add_widget(close_button)
         
         popup.open()
+        
+        # Auto-dismiss after 3 seconds if requested
+        if auto_dismiss:
+            Clock.schedule_once(lambda dt: popup.dismiss(), 3)
 
 
 if __name__ == '__main__':