fix: replace bare except clauses with except Exception

Bare `except:` catches BaseException including KeyboardInterrupt and
SystemExit. Replaced 4 instances with `except Exception:`.

Author: haosenwang1018

src/biz_layer/mem_db_operations.py

@@ -143,7 +143,7 @@ def _convert_timestamp_to_time(
             try:
                 dt = from_iso_format(timestamp)
                 return to_iso_format(dt)
-            except:
+            except Exception:
                 # If parsing fails, return string directly
                 return timestamp
         else:

src/infra_layer/adapters/out/search/repository/episodic_memory_milvus_repository.py

@@ -124,7 +124,7 @@ async def create_and_save_episodic_memory(
                 metadata_json = metadata
                 try:
                     metadata_dict = json.loads(metadata)
-                except:
+                except Exception:
                     metadata_dict = {}
 
             # Prepare entity data

tests/test_conv_memcell_extractor.py

@@ -37,7 +37,7 @@ def get_llm_provider() -> LLMProvider:
     try:
         # Try to get from DI container
         return get_bean_by_type(LLMProvider)
-    except:
+    except Exception:
         # If not found in DI container, create directly
         logger.info("LLMProvider not found in DI container, creating directly...")
         return LLMProvider("openai")

tests/test_group_user_profile_memory_raw_repository.py

@@ -528,7 +528,7 @@ async def test_batch_get_by_user_groups():
         for user_id, group_id, _ in test_data:
             try:
                 await repo.delete_by_user_group(user_id, group_id)
-            except:
+            except Exception:
                 pass
         raise