refactor(archive): move unused modules to archive/

Archive legacy framework and utility modules that are no longer
referenced by the active core (datasource/ and rotation/):

- framework/ -> archive/framework/
- framework_v2/ -> archive/framework_v2/
- strategies/ -> archive/strategies/
- config/ -> archive/config/
- visualization/ -> archive/visualization/
- scripts/ -> archive/scripts/
- tests/ -> archive/tests/
- run_rotation.py, run_us_rotation.py -> archive/single_files/
- compare_*.py, test_api_dates.py -> archive/single_files/

archive/framework_v2/core/signal.py

@@ -0,0 +1,57 @@
+"""
+信号生成器抽象基类
+"""
+
+from abc import ABC, abstractmethod
+import pandas as pd
+
+
+class SignalGenerator(ABC):
+    """
+    信号生成器抽象基类
+    
+    所有信号生成器必须实现 generate 方法
+    """
+    
+    mode: str = "base"
+    
+    def __init__(self, **params):
+        """
+        初始化信号生成器参数
+        
+        Args:
+            **params: 信号参数（如 select_num, rebalance_days 等）
+        """
+        self._params = params
+    
+    @abstractmethod
+    def generate(self, factor_data: pd.DataFrame) -> pd.DataFrame:
+        """
+        生成交易信号
+        
+        Args:
+            factor_data: 因子数据 DataFrame
+        
+        Returns:
+            信号 DataFrame，必须包含 'signal' 列
+        """
+        pass
+    
+    def validate_factor_data(self, factor_data: pd.DataFrame) -> bool:
+        """
+        验证因子数据是否有效
+        
+        Args:
+            factor_data: 因子数据
+        
+        Returns:
+            True 如果数据有效
+        """
+        if factor_data.empty:
+            return False
+        
+        return True
+    
+    def __repr__(self) -> str:
+        params_str = ', '.join([f"{k}={v}" for k, v in self._params.items()])
+        return f"{self.__class__.__name__}({params_str})"