Add handling for database serialization errors in import processing

- Add 'could not serialize access' and 'concurrent update' to scalable error detection
- Add informative messages when database serialization conflicts are detected
- Reduce chunk size and retry when serialization errors occur
This addresses the 'could not serialize access due to concurrent update' errors
that were causing import failures by treating them as scalable errors that can
be resolved by reducing batch size.

Author: bosd

src/odoo_data_flow/import_threaded.py

@@ -642,6 +642,8 @@ def _execute_load_batch(
                 or "gateway" in error_str
                 or "proxy" in error_str
                 or "timeout" in error_str
+                or "could not serialize access" in error_str
+                or "concurrent update" in error_str
             )
 
             if is_scalable_error and chunk_size > 1:
@@ -650,6 +652,15 @@ def _execute_load_batch(
                     f"[yellow]WARN:[/] Batch {batch_number} hit scalable error. "
                     f"Reducing chunk size to {chunk_size} and retrying."
                 )
+                if (
+                    "could not serialize access" in error_str
+                    or "concurrent update" in error_str
+                ):
+                    progress.console.print(
+                        "[yellow]INFO:[/] Database serialization conflict detected. "
+                        "This is often caused by concurrent processes updating the same records. "
+                        "Retrying with smaller batch size."
+                    )
                 continue
 
             clean_error = str(e).strip().replace("\n", " ")