fix(desktop): run bundled backend from writable data dir

common/log.py

@@ -33,15 +33,28 @@ def _reset_logger(log):
             datefmt="%Y-%m-%d %H:%M:%S",
         )
     )
-    file_handle = logging.FileHandler(_log_path(), encoding="utf-8")
-    file_handle.setFormatter(
-        logging.Formatter(
-            "[%(levelname)s][%(asctime)s][%(filename)s:%(lineno)d] - %(message)s",
-            datefmt="%Y-%m-%d %H:%M:%S",
-        )
-    )
-    log.addHandler(file_handle)
     log.addHandler(console_handle)
+    # File logging is best-effort: if the log path isn't writable (e.g. a
+    # packaged app installed under Program Files run by a non-admin user, with
+    # an unwritable CWD), fall back to console-only instead of crashing the
+    # whole process at import time.
+    try:
+        file_handle = logging.FileHandler(_log_path(), encoding="utf-8")
+        file_handle.setFormatter(
+            logging.Formatter(
+                "[%(levelname)s][%(asctime)s][%(filename)s:%(lineno)d] - %(message)s",
+                datefmt="%Y-%m-%d %H:%M:%S",
+            )
+        )
+        log.addHandler(file_handle)
+    except OSError:
+        console_handle.handle(
+            logging.LogRecord(
+                "log", logging.WARNING, __file__, 0,
+                "[log] file logging disabled (log path not writable): %s",
+                (_log_path(),), None,
+            )
+        )
 
 
 def _get_logger():