Add hub strategy calculator page with trend and roll risk-based sizing.

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

manual_trading_hub/hub.py

@@ -702,6 +702,7 @@ def root_redirect():
 
 @app.get("/monitor")
 @app.get("/plan")
+@app.get("/calculator")
 @app.get("/market")
 @app.get("/archive")
 @app.get("/dashboard")
@@ -793,6 +794,7 @@ class SettingsDisplayBody(BaseModel):
     show_nav_plan: bool = True
     show_nav_archive: bool = True
     show_nav_ai: bool = True
+    show_nav_calculator: bool = True
 
 
 class SettingsBody(BaseModel):
@@ -819,6 +821,72 @@ def api_save_settings(body: SettingsBody):
     return {"ok": True, "settings": load_settings()}
 
 
+class TrendCalculatorBody(BaseModel):
+    direction: str = "long"
+    capital_usdt: float = Field(gt=0)
+    risk_percent: float = Field(gt=0, le=100)
+    leverage: int = Field(ge=1, le=125)
+    entry_price: float = Field(gt=0)
+    stop_loss: float = Field(gt=0)
+    add_upper: float = Field(gt=0)
+    take_profit: float = Field(gt=0)
+    dca_legs: int = Field(default=5, ge=1, le=20)
+    contract_size: float = Field(default=1.0, gt=0)
+
+
+class RollCalculatorBody(BaseModel):
+    direction: str = "long"
+    capital_usdt: float = Field(gt=0)
+    risk_percent: float = Field(gt=0, le=100)
+    qty_existing: float = Field(gt=0)
+    entry_existing: float = Field(gt=0)
+    take_profit: float = Field(gt=0)
+    add_price: float = Field(gt=0)
+    new_stop_loss: float = Field(gt=0)
+    legs_done: int = Field(default=0, ge=0, le=10)
+
+
+@app.post("/api/calculator/trend")
+def api_calculator_trend(body: TrendCalculatorBody):
+    from hub_calculator_lib import calc_trend_calculator
+
+    data, err = calc_trend_calculator(
+        direction=body.direction,
+        capital_usdt=body.capital_usdt,
+        risk_percent=body.risk_percent,
+        leverage=body.leverage,
+        entry_price=body.entry_price,
+        stop_loss=body.stop_loss,
+        add_upper=body.add_upper,
+        take_profit=body.take_profit,
+        dca_legs=body.dca_legs,
+        contract_size=body.contract_size,
+    )
+    if err:
+        return JSONResponse({"ok": False, "msg": err}, status_code=400)
+    return {"ok": True, "data": data}
+
+
+@app.post("/api/calculator/roll")
+def api_calculator_roll(body: RollCalculatorBody):
+    from hub_calculator_lib import calc_roll_calculator
+
+    data, err = calc_roll_calculator(
+        direction=body.direction,
+        capital_usdt=body.capital_usdt,
+        risk_percent=body.risk_percent,
+        qty_existing=body.qty_existing,
+        entry_existing=body.entry_existing,
+        take_profit=body.take_profit,
+        add_price=body.add_price,
+        new_stop_loss=body.new_stop_loss,
+        legs_done=body.legs_done,
+    )
+    if err:
+        return JSONResponse({"ok": False, "msg": err}, status_code=400)
+    return {"ok": True, "data": data}
+
+
 def _find_exchange_by_key(exchange_key: str) -> dict | None:
     key = (exchange_key or "").strip().lower()
     if not key: