Add debug logging to diagnose iOS stat date issue

iOS helper: log raw stat keys+values for first file to stderr.
IosConnector: already logs stderr at WARN level.
logback.xml: print DEBUG+ for photophetch package to console so
stat output is visible when running ./gradlew run.

src/main/resources/scripts/photophetch-ios-helper.py

@@ -69,6 +69,7 @@ async def cmd_list_photos():
             return
 
         photos = []
+        debug_logged = False  # log raw stat for first file to help debug date issues
 
         for folder in sorted(dcim_entries):
             folder_path = f'/DCIM/{folder}'
@@ -89,6 +90,10 @@ async def cmd_list_photos():
                 date_iso = None
                 try:
                     info = await afc.stat(device_path)
+                    if not debug_logged:
+                        print(f'DEBUG stat keys: {list(info.keys())}', file=sys.stderr)
+                        print(f'DEBUG stat values: {dict(info)}', file=sys.stderr)
+                        debug_logged = True
                     size_bytes = int(info.get('st_size', 0))
                     mtime_raw = int(info.get('st_mtime', 0))
                     # Determine if nanoseconds (>1e15) or seconds (>1e9)