refactor: 统一日志管理 + 数据库索引优化

- db/schema.py: 添加 4 个复合索引优化查询性能
  - idx_user_schedules_user_enabled
  - idx_schedule_execution_logs_schedule_id/user_id/status
- db/users.py: print → logger，密码升级日志改为记录 user_id
- crypto_utils.py: print → logger
- password_utils.py: print → logger

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

password_utils.py

@@ -4,6 +4,8 @@
 """
 import bcrypt
 import hashlib
+from app_logger import get_logger
+logger = get_logger(__name__)
 
 
 def hash_password_bcrypt(password):
@@ -35,7 +37,7 @@ def verify_password_bcrypt(password, password_hash):
         return bcrypt.checkpw(password.encode('utf-8'),
                              password_hash.encode('utf-8'))
     except Exception as e:
-        print(f"bcrypt验证异常: {e}")
+        logger.error(f"bcrypt验证异常: {e}")
         return False
 
 
@@ -70,5 +72,5 @@ def verify_password_sha256(password, password_hash):
         computed_hash = hashlib.sha256(password.encode()).hexdigest()
         return computed_hash == password_hash
     except Exception as e:
-        print(f"SHA256验证异常: {e}")
+        logger.error(f"SHA256验证异常: {e}")
         return False