fix: Multiple bug fixes and improvements

- Fix Invalid Date display in Dashboard notifications
- Fix timezone offset (8 hours) in Trading Records time display
- Fix position closing failures due to commission discrepancies (fetch actual exchange position size for reduce_only orders)
- Fix IBKR connection error 'no current event loop in thread' by ensuring asyncio event loop exists
- Fix duplicate orders on same candle by extending signal deduplication to close signals
- Add responsive design for Profile page (mobile-friendly)
- Remove unused strategy_code module and database table
- Fix LLM service to support multiple providers (OpenRouter, OpenAI, DeepSeek, Grok, Google)
- Add auto-detection of configured LLM provider based on API key availability
- Fix AI code generation to use unified LLMService with proper provider selection
- Fix crypto symbol format handling (ETH/USDT no longer becomes ETH/USDT/USDT)
- Fix Commission display showing '0E-8' in Trading Records
- Fix P&L display for signal-only trades (show '--' for unrealized P&L)
- Fix OAuth login not updating last_login_at for new users
- Add migration script for notification_settings column
- Update env.example with new LLM provider configurations
- Remove ESLint rule that was not defined in config

backend_api_python/app/services/agents/tools.py

@@ -137,7 +137,8 @@ class AgentTools:
             
             elif market == 'Crypto':
                 exchange = self._ccxt_exchange()
-                symbol_pair = f'{symbol}/USDT'
+                # Handle symbol format: ETH/USDT -> ETH/USDT, ETH -> ETH/USDT
+                symbol_pair = symbol if '/' in symbol else f'{symbol}/USDT'
                 start_time = int((datetime.now() - timedelta(days=days)).timestamp())
                 # CCXT timeframes: 1d, 1h, 4h ...
                 ccxt_tf = tf if tf in ["1d", "1h", "4h"] else "1d"
@@ -233,7 +234,8 @@ class AgentTools:
                     }
             elif market == 'Crypto':
                 exchange = self._ccxt_exchange()
-                symbol_pair = f'{symbol}/USDT'
+                # Handle symbol format: ETH/USDT -> ETH/USDT, ETH -> ETH/USDT
+                symbol_pair = symbol if '/' in symbol else f'{symbol}/USDT'
                 ticker = exchange.fetch_ticker(symbol_pair)
                 if ticker:
                     return {