refactor: 缠论引擎迁入 chan/ 分层解耦，指标外置

将核心结构、指标与分析拆到 chan/{core,indicators,analysis,pipeline}；
根目录保留兼容 shim；strategies 改为从 chan 包导入；买卖点经 bsp_macd 与 MACD 接合。

Co-authored-by: Cursor <cursoragent@cursor.com>

chan/indicators/__init__.py

@@ -0,0 +1,13 @@
+"""指标外置层：不依赖笔/段/中枢，只产出按 idx 对齐的序列。"""
+
+from .config import IndicatorConfig
+from .engine import IndicatorEngine
+from .store import IndicatorStore
+from .attach import attach_indicators_for_compat
+
+__all__ = [
+    "IndicatorConfig",
+    "IndicatorEngine",
+    "IndicatorStore",
+    "attach_indicators_for_compat",
+]