ADD: added first version

internal/model/bar.go

@@ -0,0 +1,13 @@
+package model
+
+import "time"
+
+type Bar struct {
+	Symbol string
+	Time   time.Time
+	Open   float64
+	High   float64
+	Low    float64
+	Close  float64
+	Volume int64
+}

internal/model/trade.go

@@ -0,0 +1,14 @@
+package model
+
+import "time"
+
+type Trade struct {
+	Time       time.Time
+	Symbol     string
+	Side       string
+	Price      float64
+	Qty        int
+	Cash       float64
+	StopPrice  float64 // ATR-based stop
+	TakeProfit float64 // ATR-based take profit
+}

internal/model/types.go

@@ -0,0 +1,10 @@
+package model
+
+type Signal int
+
+const (
+	Hold Signal = iota
+	Buy
+	Sell
+)
+