diff --git a/backend/export_manager.py b/backend/export_manager.py
index cdcf9e3..35e7792 100644
--- a/backend/export_manager.py
+++ b/backend/export_manager.py
@@ -281,7 +281,7 @@ class ExportManager:
                     try:
                         if len(str(cell.value)) > max_length:
                             max_length = len(str(cell.value))
-                    except BaseException:
+                    except (AttributeError, TypeError, ValueError):
                         pass
                 adjusted_width = min(max_length + 2, 50)
                 worksheet.column_dimensions[column_letter].width = adjusted_width
diff --git a/backend/localization_manager.py b/backend/localization_manager.py
index 2d42b07..6325c31 100644
--- a/backend/localization_manager.py
+++ b/backend/localization_manager.py
@@ -1337,7 +1337,7 @@ class LocalizationManager:
                         return dates.format_time(dt, locale=locale)
                     else:
                         return dates.format_datetime(dt, locale=locale)
-                except BaseException:
+                except (ValueError, AttributeError):
                     pass
             return dt.strftime(fmt)
         except Exception as e:
@@ -1354,7 +1354,7 @@ class LocalizationManager:
                     return numbers.format_decimal(
                         number, locale=locale, decimal_quantization=(decimal_places is not None)
                     )
-                except BaseException:
+                except (ValueError, AttributeError):
                     pass
             if decimal_places is not None:
                 return f"{number:,.{decimal_places}f}"
@@ -1369,7 +1369,7 @@ class LocalizationManager:
                 try:
                     locale = Locale.parse(language.replace("_", "-"))
                     return numbers.format_currency(amount, currency, locale=locale)
-                except BaseException:
+                except (ValueError, AttributeError):
                     pass
             return f"{currency} {amount:,.2f}"
         except Exception as e:
diff --git a/backend/main.py b/backend/main.py
index f3e6160..8c65027 100644
--- a/backend/main.py
+++ b/backend/main.py
@@ -59,7 +59,13 @@ except ImportError:
     TINGWU_AVAILABLE = False
 
 try:
-    from db_manager import Entity, EntityMention, get_db_manager
+    from db_manager import (
+        AttributeTemplate,
+        Entity,
+        EntityAttribute,
+        EntityMention,
+        get_db_manager,
+    )
 
     DB_AVAILABLE = True
 except ImportError as e:
@@ -2016,7 +2022,7 @@ async def agent_suggest(project_id: str, _=Depends(verify_api_key)):
         try:
             data = json.loads(json_match.group())
             return data
-        except BaseException:
+        except (json.JSONDecodeError, ValueError):
             pass
 
     return {"suggestions": []}
@@ -3060,7 +3066,7 @@ async def export_report_pdf_endpoint(project_id: str, _=Depends(verify_api_key))
             reasoner = get_knowledge_reasoner()
             summary_result = reasoner.generate_project_summary(project_id, db)
             summary = summary_result.get("summary", "")
-        except BaseException:
+        except Exception:
             pass
 
     export_mgr = get_export_manager()
diff --git a/backend/neo4j_manager.py b/backend/neo4j_manager.py
index c79bfdc..409ccd3 100644
--- a/backend/neo4j_manager.py
+++ b/backend/neo4j_manager.py
@@ -134,7 +134,7 @@ class Neo4jManager:
         try:
             self._driver.verify_connectivity()
             return True
-        except BaseException:
+        except Exception:
             return False
 
     def init_schema(self) -> None:
diff --git a/backend/performance_manager.py b/backend/performance_manager.py
index 3fe9e82..0b98a8e 100644
--- a/backend/performance_manager.py
+++ b/backend/performance_manager.py
@@ -234,7 +234,7 @@ class CacheManager:
         """估算缓存条目大小"""
         try:
             return len(json.dumps(value, ensure_ascii=False).encode("utf-8"))
-        except BaseException:
+        except (TypeError, ValueError):
             return 1024  # 默认估算
 
     def _evict_lru(self, required_space: int = 0) -> None:
diff --git a/backend/plugin_manager.py b/backend/plugin_manager.py
index 4933edb..e0d74c2 100644
--- a/backend/plugin_manager.py
+++ b/backend/plugin_manager.py
@@ -1337,7 +1337,7 @@ class WebDAVSyncManager:
             remote_project_path = f"{sync.remote_path}/{sync.project_id}"
             try:
                 client.mkdir(remote_project_path)
-            except BaseException:
+            except (OSError, IOError):
                 pass  # 目录可能已存在
 
             # 获取项目数据
diff --git a/backend/security_manager.py b/backend/security_manager.py
index d916a25..0fedb52 100644
--- a/backend/security_manager.py
+++ b/backend/security_manager.py
@@ -297,9 +297,12 @@ class SecurityManager:
         """)
 
         # 创建索引
-        cursor.execute("CREATE INDEX IF NOT EXISTS idx_audit_logs_user ON audit_logs(user_id)")
         cursor.execute(
-            "CREATE INDEX IF NOT EXISTS idx_audit_logs_resource ON audit_logs(resource_type, resource_id)"
+            "CREATE INDEX IF NOT EXISTS idx_audit_logs_user ON audit_logs(user_id)"
+        )
+        cursor.execute(
+            "CREATE INDEX IF NOT EXISTS idx_audit_logs_resource "
+            "ON audit_logs(resource_type, resource_id)"
         )
         cursor.execute(
             "CREATE INDEX IF NOT EXISTS idx_audit_logs_action ON audit_logs(action_type)"