fix: Improve exception handling in reconnect example to prevent resource leaks and eliminate code duplication

- Add proper interface cleanup in BLEError handler to prevent resource leaks
- Centralize retry logic to eliminate code duplication across exception handlers
- Use try/except/finally pattern to ensure consistent cleanup
- Add sys import for exception handling

Author: jeremiah-k

examples/reconnect_example.py

@@ -10,6 +10,7 @@
 The application can then listen for this event and attempt to create a new
 BLEInterface instance to re-establish the connection, as shown in this example.
 """
+import sys
 import threading
 import time
 
@@ -57,23 +58,26 @@ def main():
 
             # We must explicitly close the old interface before creating a new one
             iface.close()
-            print("Interface closed. Reconnecting in 5 seconds...")
-            time.sleep(5)
+            print("Disconnected normally.")
 
-        except meshtastic.ble_interface.BLEInterface.BLEError as e:
-            print(f"Connection failed: {e}")
-            print("Retrying in 5 seconds...")
-            time.sleep(5)
         except KeyboardInterrupt:
             print("Exiting...")
-            # Make sure to close the interface on exit
-            if iface:
-                iface.close()
             break
+        except meshtastic.ble_interface.BLEInterface.BLEError as e:
+            print(f"Connection failed: {e}")
         except Exception as e:
             print(f"An unexpected error occurred: {e}")
-            if iface:
+        finally:
+            # Close the interface on any exception to prevent resource leaks
+            # (except KeyboardInterrupt which breaks the loop)
+            current_exception = sys.exc_info()[1]
+            if iface and current_exception and not isinstance(current_exception, KeyboardInterrupt):
                 iface.close()
+                print("Interface closed.")
+        
+        # If we get here and didn't break due to KeyboardInterrupt, retry
+        current_exception = sys.exc_info()[1]
+        if not current_exception or isinstance(current_exception, (meshtastic.ble_interface.BLEInterface.BLEError, Exception)):
             print("Retrying in 5 seconds...")
             time.sleep(5)