feat(api): 回测结果接口（strategy list/params + equity-curve/daily-pnl/trades + kline）

- strategy_registry 枚举 vnpy_ctastrategy 策略（兜底 STRATEGY_NAMES）
- /strategy/list、/strategy/{name}/params
- /task/{id}/equity-curve、/daily-pnl、/trades（BacktestResult JSON 化）
- /kline（read_db_daily 历史 K 线）
- 9 tests passed（4 strategy_registry + 5 routes）

sanguo_api/strategy_registry.py

@@ -0,0 +1,56 @@
+"""Enumerate vnpy_ctastrategy CTA strategies + their parameters.
+
+Used by the backtest UI dropdown and dynamic parameter form. Falls back to a
+static name list when vnpy_ctastrategy is not importable (e.g. local dev).
+Task S1.3.
+"""
+from __future__ import annotations
+
+import importlib
+import pkgutil
+
+# Fallback strategy names (when vnpy_ctastrategy import fails).
+STRATEGY_NAMES: list[str] = ["DoubleMaStrategy", "BollChannelStrategy", "AtrRsiStrategy"]
+
+
+def _load_strategy_classes() -> dict[str, type]:
+    """Import all Strategy classes from vnpy_ctastrategy.strategies."""
+    classes: dict[str, type] = {}
+    try:
+        mod = importlib.import_module("vnpy_ctastrategy.strategies")
+        for _, name, _ in pkgutil.iter_modules(mod.__path__):
+            try:
+                m = importlib.import_module(f"vnpy_ctastrategy.strategies.{name}")
+                for attr in dir(m):
+                    obj = getattr(m, attr)
+                    if isinstance(obj, type) and attr.endswith("Strategy") and hasattr(obj, "parameters"):
+                        classes[attr] = obj
+            except Exception:
+                continue
+    except Exception:
+        pass
+    return classes
+
+
+def list_strategies() -> list[dict]:
+    """Return [{name, class_name}, ...] for the UI dropdown."""
+    classes = _load_strategy_classes()
+    if classes:
+        return [{"name": n, "class_name": n} for n in sorted(classes)]
+    return [{"name": n, "class_name": n} for n in STRATEGY_NAMES]
+
+
+def strategy_params(name: str) -> dict:
+    """Return {parameters: [...], defaults: {...}} for a strategy's dynamic form."""
+    classes = _load_strategy_classes()
+    cls = classes.get(name)
+    if cls is None:
+        return {"parameters": [], "defaults": {}}
+    params = list(getattr(cls, "parameters", []))
+    defaults = {p: getattr(cls, p, None) for p in params}
+    return {"parameters": params, "defaults": defaults}
+
+
+def get_strategy_class(name: str) -> type | None:
+    """Return the strategy class by name (None if unavailable)."""
+    return _load_strategy_classes().get(name)