Add configurable SIM equity (default 10k) and strategy docs.

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

backend/app/api/settings.py

@@ -2,12 +2,13 @@ from __future__ import annotations
 
 from typing import Annotated
 
-from fastapi import APIRouter, Depends
+from fastapi import APIRouter, Depends, HTTPException
 from pydantic import BaseModel, Field
 
 from ..config import get_settings
 from ..models.db import get_db
 from ..sim.ledger import Ledger
+from ..sim.matcher import Matcher
 from .auth import require_user
 
 router = APIRouter(prefix="/api/settings", tags=["settings"])
@@ -38,7 +39,7 @@ class StrategySettingsBody(BaseModel):
     premium_exit_multiple: float | None = Field(default=None, ge=0.1, le=100)
     rest_seconds: int | None = Field(default=None, ge=0, le=3600)
     skip_weekends: bool | None = None
-    initial_equity: float | None = Field(default=None, ge=1000)
+    initial_equity: float | None = Field(default=None, ge=1000, le=10_000_000)
     leverage: float | None = Field(default=None, ge=1, le=125)
     min_option_hours: float | None = Field(default=None, ge=1, le=720)
     min_option_leverage: float | None = Field(default=None, ge=1, le=10000)
@@ -116,8 +117,27 @@ async def put_strategy_settings(
     _user: Annotated[str, Depends(require_user)],
 ) -> dict:
     db = get_db()
+    s = get_settings()
     data = body.model_dump(exclude_none=True)
+    equity_to_apply: float | None = None
+    if "initial_equity" in data:
+        new_eq = float(data["initial_equity"])
+        old_eq = float(
+            db.get_setting("initial_equity", str(s.initial_equity)) or s.initial_equity
+        )
+        if abs(new_eq - old_eq) > 1e-9:
+            if Matcher(db).has_open_position():
+                raise HTTPException(
+                    status_code=409,
+                    detail="有未平仓，无法重置模拟资金；请先平仓后再改",
+                )
+            equity_to_apply = new_eq
     for k, v in data.items():
         if k in KEYS:
             db.set_setting(k, str(v))
+    if equity_to_apply is not None:
+        Ledger(db).reset_equity(
+            equity_to_apply,
+            note=f"设置模拟资金={equity_to_apply:.2f}",
+        )
     return _read_settings()