refactor: 缠论引擎包化与 Web 分层（ECR-001）

将根目录引擎迁入 chanlun/ 并保留兼容 shim；拆分 TF_DF 与 web 服务；
前端模块化；strategies 改用 chanlun 导入；补充 ESS 文档与 golden 回归。

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

web/tests/test_analyze_contract.py

@@ -0,0 +1,29 @@
+""" /api/analyze 契约冒烟：关键字段存在于契约清单。"""
+from __future__ import annotations
+
+import json
+import sys
+from pathlib import Path
+
+ROOT = Path(__file__).resolve().parents[2]
+sys.path.insert(0, str(ROOT))
+sys.path.insert(0, str(ROOT / "web"))
+
+
+def test_analyze_route_registered():
+    from app import app
+
+    rules = {r.rule for r in app.url_map.iter_rules()}
+    assert "/api/analyze" in rules
+    assert "/api/chart_metadata" in rules
+    assert "/" in rules
+    assert "/chan_tv" in rules
+
+
+def test_contract_keys_stable():
+    keys = json.loads(
+        (ROOT / "tests" / "fixtures" / "analyze_contract_keys.json").read_text(
+            encoding="utf-8"
+        )
+    )
+    assert "bi_list" in keys and "seg_list" in keys