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/pages/TraderDashboardPage.tsx

@@ -1,15 +1,15 @@
 import { useEffect, useState, useRef } from 'react'
 import { mutate } from 'swr'
 import { api } from '../lib/api'
-import { ChartTabs } from '../components/ChartTabs'
-import { DecisionCard } from '../components/DecisionCard'
-import { PositionHistory } from '../components/PositionHistory'
-import { PunkAvatar, getTraderAvatar } from '../components/PunkAvatar'
+import { ChartTabs } from '../components/charts/ChartTabs'
+import { DecisionCard } from '../components/trader/DecisionCard'
+import { PositionHistory } from '../components/trader/PositionHistory'
+import { PunkAvatar, getTraderAvatar } from '../components/common/PunkAvatar'
 import { confirmToast, notify } from '../lib/notify'
 import { formatPrice, formatQuantity } from '../utils/format'
 import { t, type Language } from '../i18n/translations'
 import { LogOut, Loader2, Eye, EyeOff, Copy, Check } from 'lucide-react'
-import { DeepVoidBackground } from '../components/DeepVoidBackground'
+import { DeepVoidBackground } from '../components/common/DeepVoidBackground'
 import { GridRiskPanel } from '../components/strategy/GridRiskPanel'
 import type {
     SystemStatus,