refactor: restructure project directories for better modularity

- Delete llm/ dead code (3 files, zero references)
- Split mcp/ into sub-packages: mcp/provider/ (8 providers) and
  mcp/payment/ (4 payment clients) with registry pattern
- Export Client internal fields and ClientHooks interface for
  sub-package access
- Split api/server.go (3892 lines) into 8 domain-specific handler files
- Split trader/auto_trader.go (2296 lines) into 5 focused files
- Reorganize web/src/components/ flat files into auth/, charts/,
  trader/, common/, modals/, backtest/ subdirectories
- Update all consumer imports to use registry-based provider creation

web/src/components/common/ModelIcons.tsx

@@ -0,0 +1,80 @@
+interface IconProps {
+  width?: number
+  height?: number
+  className?: string
+}
+
+// AI model colors for fallback display
+const MODEL_COLORS: Record<string, string> = {
+  deepseek: '#4A90E2',
+  qwen: '#9B59B6',
+  claude: '#D97757',
+  kimi: '#6366F1',
+  gemini: '#4285F4',
+  grok: '#000000',
+  openai: '#10A37F',
+  minimax: '#E45735',
+  'blockrun-base': '#2563EB',
+  'blockrun-sol': '#9945FF',
+  claw402: '#7C3AED',
+}
+
+// 获取AI模型图标的函数
+export const getModelIcon = (modelType: string, props: IconProps = {}) => {
+  // 支持完整ID或类型名
+  const type = modelType.includes('_') ? modelType.split('_').pop() : modelType
+
+  let iconPath: string | null = null
+
+  switch (type) {
+    case 'deepseek':
+      iconPath = '/icons/deepseek.svg'
+      break
+    case 'qwen':
+      iconPath = '/icons/qwen.svg'
+      break
+    case 'claude':
+      iconPath = '/icons/claude.svg'
+      break
+    case 'kimi':
+      iconPath = '/icons/kimi.svg'
+      break
+    case 'gemini':
+      iconPath = '/icons/gemini.svg'
+      break
+    case 'grok':
+      iconPath = '/icons/grok.svg'
+      break
+    case 'openai':
+      iconPath = '/icons/openai.svg'
+      break
+    case 'minimax':
+      iconPath = '/icons/minimax.svg'
+      break
+    case 'blockrun-base':
+    case 'blockrun-sol':
+      iconPath = '/icons/blockrun.svg'
+      break
+    case 'claw402':
+      iconPath = '/icons/claw402.png'
+      break
+    default:
+      return null
+  }
+
+  return (
+    <img
+      src={iconPath}
+      alt={`${type} icon`}
+      width={props.width || 24}
+      height={props.height || 24}
+      className={props.className}
+    />
+  )
+}
+
+// 获取模型颜色（用于没有图标时的fallback）
+export const getModelColor = (modelType: string): string => {
+  const type = modelType.includes('_') ? modelType.split('_').pop() : modelType
+  return MODEL_COLORS[type || ''] || '#60a5fa'
+}