refactor: Improve exception handling and logging in authentication and playlist services; enhance code readability and structure

app/api/v1/auth.py

@@ -181,7 +181,9 @@ async def logout(
                 user_id = int(user_id_str)
                 user = await auth_service.get_current_user(user_id)
                 logger.info("Found user from access token: %s", user.email)
-        except (HTTPException, Exception) as e:
+        except HTTPException as e:
+            logger.info("Access token validation failed: %s", str(e))
+        except Exception as e:  # noqa: BLE001
             logger.info("Access token validation failed: %s", str(e))
 
     # If no user found, try refresh token
@@ -193,7 +195,9 @@ async def logout(
                 user_id = int(user_id_str)
                 user = await auth_service.get_current_user(user_id)
                 logger.info("Found user from refresh token: %s", user.email)
-        except (HTTPException, Exception) as e:
+        except HTTPException as e:
+            logger.info("Refresh token validation failed: %s", str(e))
+        except Exception as e:  # noqa: BLE001
             logger.info("Refresh token validation failed: %s", str(e))
 
     # If we found a user, revoke their refresh token
@@ -484,7 +488,6 @@ async def change_password(
         await auth_service.change_user_password(
             current_user, request.current_password, request.new_password,
         )
-        return {"message": "Password changed successfully"}
     except ValueError as e:
         raise HTTPException(
             status_code=status.HTTP_400_BAD_REQUEST,
@@ -496,6 +499,8 @@ async def change_password(
             status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
             detail="Failed to change password",
         ) from e
+    else:
+        return {"message": "Password changed successfully"}
 
 
 @router.get("/user-providers")