feat: Add powerful flexible strategy system

Strategy Builder:
- Create strategies from natural language
- Grid trading strategy
- DCA (Dollar Cost Averaging) strategy
- Trend following (EMA crossover) strategy
- Custom rule-based strategies

Strategy Components:
- Entry/exit rules with indicators (RSI, EMA, MACD, etc.)
- Position sizing (fixed, percent, risk-based, kelly)
- Risk management (max drawdown, daily loss limit, cooldown)
- Leverage config (fixed, dynamic, per-symbol, per-volatility)
- Time-based rules (trading hours, hold time limits)
- AI enhancement (confidence threshold, personality)

11 New Tools:
- create_strategy - Natural language strategy creation
- create_grid_strategy - Grid trading setup
- create_dca_strategy - DCA setup
- create_trend_strategy - Trend following setup
- list_smart_strategies - List all strategies
- get_strategy_details - Strategy details
- update_strategy - Modify strategy settings
- activate_strategy - Start trading
- deactivate_strategy - Stop trading
- delete_strategy - Remove strategy
- get_strategy_templates - Show available templates

Total tools now: 24 (13 trading + 11 strategy)

main.go

@@ -157,6 +157,10 @@ func main() {
 			tradingTools := assistant.NewTradingTools(traderManager, st)
 			smartAgent.RegisterTools(tradingTools.GetAllTools()...)
 
+			// Register strategy tools
+			strategyTools := assistant.NewStrategyTools(st)
+			smartAgent.RegisterTools(strategyTools.GetAllTools()...)
+
 			// Create and start Telegram bot
 			var err error
 			telegramBot, err = telegram.NewBot(telegramConfig, smartAgent.Agent)