refactor: 继续拆分大型模块并增强模块注册健壮性

后端:
- chat_handler_base 错误处理函数提取到 chat_error_utils 子模块
- CLI mixin 引入 CliHandlerProtocol 协议类改善类型标注
- aware_scheduler 拆分为 _candidate_builder 和 _candidate_sorter 子模块
- usage recording 拆分为 _billing_integration 和 _recording_helpers 子模块
- ModuleRegistry 添加循环依赖检测，将写操作从查询方法分离到 reconcile_module_state
- 修正 plugin manager 入度注释

前端:
- 路由守卫逻辑拆分为独立 guards 模块
- ProviderManagement 拆分为 TableHeader/TableRow/BalanceCell/MobileCard 子组件
- SystemSettings 拆分为多个 Section 子组件和 composables
- 提取 useEndpointStatus/useProviderBalance/useProviderFilters composables

测试适配重构后的子模块结构

frontend/src/features/providers/components/ProviderTableHeader.vue

@@ -0,0 +1,162 @@
+<template>
+  <div class="px-4 sm:px-6 py-3 sm:py-3.5 border-b border-border/50">
+    <div class="flex flex-col sm:flex-row sm:items-center sm:justify-between gap-3 sm:gap-4">
+      <!-- 左侧：标题 -->
+      <h3 class="text-sm sm:text-base font-semibold text-foreground shrink-0">
+        提供商管理
+      </h3>
+
+      <!-- 右侧：操作区 -->
+      <div class="flex flex-wrap items-center gap-2">
+        <!-- 搜索框 -->
+        <div class="relative">
+          <Search class="absolute left-2.5 top-1/2 -translate-y-1/2 h-3.5 w-3.5 text-muted-foreground/70 z-10 pointer-events-none" />
+          <Input
+            id="provider-search"
+            :model-value="searchQuery"
+            type="text"
+            placeholder="搜索提供商..."
+            class="w-32 sm:w-44 pl-8 pr-3 h-8 text-sm bg-muted/30 border-border/50 focus:border-primary/50 transition-colors"
+            @update:model-value="$emit('update:searchQuery', $event)"
+          />
+        </div>
+
+        <!-- 状态筛选 -->
+        <Select
+          :model-value="filterStatus"
+          @update:model-value="$emit('update:filterStatus', $event)"
+        >
+          <SelectTrigger class="w-20 sm:w-28 h-8 text-xs border-border/60">
+            <SelectValue placeholder="全部状态" />
+          </SelectTrigger>
+          <SelectContent>
+            <SelectItem
+              v-for="status in statusFilters"
+              :key="status.value"
+              :value="status.value"
+            >
+              {{ status.label }}
+            </SelectItem>
+          </SelectContent>
+        </Select>
+
+        <!-- API 格式筛选 -->
+        <Select
+          :model-value="filterApiFormat"
+          @update:model-value="$emit('update:filterApiFormat', $event)"
+        >
+          <SelectTrigger class="w-20 sm:w-28 h-8 text-xs border-border/60">
+            <SelectValue placeholder="全部格式" />
+          </SelectTrigger>
+          <SelectContent>
+            <SelectItem
+              v-for="fmt in apiFormatFilters"
+              :key="fmt.value"
+              :value="fmt.value"
+            >
+              {{ fmt.label }}
+            </SelectItem>
+          </SelectContent>
+        </Select>
+
+        <!-- 模型筛选 -->
+        <Select
+          :model-value="filterModel"
+          @update:model-value="$emit('update:filterModel', $event)"
+        >
+          <SelectTrigger class="w-20 sm:w-36 h-8 text-xs border-border/60">
+            <SelectValue placeholder="全部模型" />
+          </SelectTrigger>
+          <SelectContent>
+            <SelectItem
+              v-for="model in modelFilters"
+              :key="model.value"
+              :value="model.value"
+            >
+              {{ model.label }}
+            </SelectItem>
+          </SelectContent>
+        </Select>
+
+        <!-- 重置筛选 -->
+        <Button
+          v-if="hasActiveFilters"
+          variant="ghost"
+          size="icon"
+          class="h-8 w-8"
+          title="重置筛选"
+          @click="$emit('resetFilters')"
+        >
+          <FilterX class="w-3.5 h-3.5" />
+        </Button>
+
+        <div class="hidden sm:block h-4 w-px bg-border" />
+
+        <!-- 调度策略 -->
+        <button
+          class="group inline-flex items-center gap-1.5 px-2.5 h-8 rounded-md border border-border/50 bg-muted/20 hover:bg-muted/40 hover:border-primary/40 transition-all duration-200 text-xs"
+          title="点击调整调度策略"
+          @click="$emit('openPriorityDialog')"
+        >
+          <span class="text-muted-foreground/80 hidden sm:inline">调度:</span>
+          <span class="font-medium text-foreground/90">{{ priorityModeLabel }}</span>
+          <ChevronDown class="w-3 h-3 text-muted-foreground/70 group-hover:text-foreground transition-colors" />
+        </button>
+
+        <div class="hidden sm:block h-4 w-px bg-border" />
+
+        <!-- 操作按钮 -->
+        <Button
+          variant="ghost"
+          size="icon"
+          class="h-8 w-8"
+          title="新增提供商"
+          @click="$emit('addProvider')"
+        >
+          <Plus class="w-3.5 h-3.5" />
+        </Button>
+        <RefreshButton
+          :loading="loading"
+          @click="$emit('refresh')"
+        />
+      </div>
+    </div>
+  </div>
+</template>
+
+<script setup lang="ts">
+import { Search, Plus, ChevronDown, FilterX } from 'lucide-vue-next'
+import Button from '@/components/ui/button.vue'
+import Input from '@/components/ui/input.vue'
+import Select from '@/components/ui/select.vue'
+import SelectTrigger from '@/components/ui/select-trigger.vue'
+import SelectValue from '@/components/ui/select-value.vue'
+import SelectContent from '@/components/ui/select-content.vue'
+import SelectItem from '@/components/ui/select-item.vue'
+import RefreshButton from '@/components/ui/refresh-button.vue'
+import type { FilterOption } from '@/features/providers/composables/useProviderFilters'
+
+defineProps<{
+  searchQuery: string
+  filterStatus: string
+  filterApiFormat: string
+  filterModel: string
+  statusFilters: FilterOption[]
+  apiFormatFilters: FilterOption[]
+  modelFilters: FilterOption[]
+  hasActiveFilters: boolean
+  priorityModeLabel: string
+  loading: boolean
+}>()
+
+defineEmits<{
+  'update:searchQuery': [value: string]
+  'update:filterStatus': [value: string]
+  'update:filterApiFormat': [value: string]
+  'update:filterModel': [value: string]
+  'resetFilters': []
+  'openPriorityDialog': []
+  'addProvider': []
+  'refresh': []
+}>()
+</script>