feat: added wallet service

server/models/wallet/model.go

@@ -1,5 +1,16 @@
 package wallet
 
+import "time"
+
+type Wallet struct {
+	Address string `db:"address" json:"address"`
+	Label *string `db:"label" json:"label,omitempty"`
+	PasswordHash string `db:"password_hash" json:"password_hash"`
+	Balance float64 `db:"balance" json:"balance"`
+	CreatedAt time.Time `db:"created_at" json:"created_at"`
+	LastActivity *time.Time `db:"last_activity" json:"last_activity,omitempty"`
+}
+
 type CreateWalletRequest struct {
 	Label *string `json:"label,omitempty"`
 	Password string `json:"password"`