refactor: delete router.go — LLM is the brain, not regex

DELETED: agent/router.go (regex-based intent routing)

The fundamental architecture was wrong. A real AI Agent doesn't use
pattern matching to understand users. It uses AI.

New flow:
1. User says anything
2. /help and /status → instant response (no AI needed)
3. Setup keywords → onboard flow
4. EVERYTHING else → LLM with full context

The LLM receives:
- System prompt with NOFXi's capabilities and behavior rules
- Real-time market data (auto-detected from mentioned symbols)
- Live trader positions and status
- User's message

The LLM decides what to do. Not regex. Not if-else. The AI.

This is what makes it an Agent, not a chatbot.

agent/i18n.go

@@ -20,8 +20,8 @@ var i18nMessages = map[string]map[string]string{
 			"Just talk to me in any language 💬",
 	},
 	"status": {
-		"zh": "📊 *NOFXi 状态*\n\n• 运行中 Traders: %d/%d\n• 监控交易对: %d\n• 时间: %s",
-		"en": "📊 *NOFXi Status*\n\n• Running Traders: %d/%d\n• Watching: %d symbols\n• Time: %s",
+		"zh": "📊 *NOFXi 状态*\n\n• Traders: %d/%d 运行中\n• 监控: %d 个交易对\n• AI: %s\n• 时间: %s",
+		"en": "📊 *NOFXi Status*\n\n• Traders: %d/%d running\n• Watching: %d symbols\n• AI: %s\n• Time: %s",
 	},
 	"no_traders": {
 		"zh": "📭 暂无 Trader。请在 Web UI 中创建和配置。",