feat(dc): Complete Tool B frontend development with UI optimization

- Implement Tool B 5-step workflow (upload, schema, processing, verify, result)
- Add back navigation button to Portal
- Optimize Step 2 field list styling to match prototype
- Fix step 3 label: 'dual-blind' to 'dual-model'
- Create API service layer with 7 endpoints
- Integrate Tool B route into DC module
- Add comprehensive TypeScript types

Components (~1100 lines):
- index.tsx: Main Tool B entry with state management
- Step1Upload.tsx: File upload and health check
- Step2Schema.tsx: Smart template configuration
- Step3Processing.tsx: Dual-model extraction progress
- Step4Verify.tsx: Conflict verification workbench
- Step5Result.tsx: Result display
- StepIndicator.tsx: Step progress component
- api/toolB.ts: API service layer

Status: Frontend complete, ready for API integration

frontend-v2/src/modules/dc/api/toolB.ts

@@ -0,0 +1,178 @@
+/**
+ * Tool B API 服务层
+ * 病历结构化机器人 API调用
+ */
+
+const API_BASE = '/api/v1/dc/tool-b';
+
+export interface HealthCheckRequest {
+  fileKey: string;
+  columnName: string;
+}
+
+export interface HealthCheckResponse {
+  status: 'good' | 'bad';
+  emptyRate: number;
+  avgLength: number;
+  totalRows: number;
+  estimatedTokens: number;
+  message: string;
+}
+
+export interface Template {
+  diseaseType: string;
+  reportType: string;
+  displayName: string;
+  fields: Array<{
+    name: string;
+    desc: string;
+    width?: string;
+  }>;
+}
+
+export interface CreateTaskRequest {
+  projectName: string;
+  fileKey: string;
+  textColumn: string;
+  diseaseType: string;
+  reportType: string;
+  targetFields: Array<{
+    name: string;
+    desc: string;
+  }>;
+}
+
+export interface CreateTaskResponse {
+  taskId: string;
+}
+
+export interface TaskProgress {
+  taskId: string;
+  status: 'pending' | 'processing' | 'completed' | 'failed';
+  progress: number;
+  totalRows: number;
+  processedRows: number;
+  conflictCount?: number;
+  estimatedTime?: string;
+  logs: string[];
+}
+
+export interface ExtractionItem {
+  id: string;
+  rowIndex: number;
+  originalText: string;
+  status: 'clean' | 'conflict';
+  extractedData: Record<string, {
+    modelA: string;
+    modelB: string;
+    chosen: string | null;
+  }>;
+}
+
+/**
+ * 健康检查API
+ */
+export async function healthCheck(request: HealthCheckRequest): Promise<HealthCheckResponse> {
+  const response = await fetch(`${API_BASE}/health-check`, {
+    method: 'POST',
+    headers: { 'Content-Type': 'application/json' },
+    body: JSON.stringify(request),
+  });
+  
+  if (!response.ok) {
+    throw new Error(`Health check failed: ${response.statusText}`);
+  }
+  
+  return await response.json();
+}
+
+/**
+ * 获取模板列表
+ */
+export async function getTemplates(): Promise<{ templates: Template[] }> {
+  const response = await fetch(`${API_BASE}/templates`);
+  
+  if (!response.ok) {
+    throw new Error(`Get templates failed: ${response.statusText}`);
+  }
+  
+  return await response.json();
+}
+
+/**
+ * 创建提取任务
+ */
+export async function createTask(request: CreateTaskRequest): Promise<CreateTaskResponse> {
+  const response = await fetch(`${API_BASE}/tasks`, {
+    method: 'POST',
+    headers: { 'Content-Type': 'application/json' },
+    body: JSON.stringify(request),
+  });
+  
+  if (!response.ok) {
+    throw new Error(`Create task failed: ${response.statusText}`);
+  }
+  
+  return await response.json();
+}
+
+/**
+ * 查询任务进度
+ */
+export async function getTaskProgress(taskId: string): Promise<TaskProgress> {
+  const response = await fetch(`${API_BASE}/tasks/${taskId}/progress`);
+  
+  if (!response.ok) {
+    throw new Error(`Get task progress failed: ${response.statusText}`);
+  }
+  
+  return await response.json();
+}
+
+/**
+ * 获取验证网格数据
+ */
+export async function getTaskItems(taskId: string): Promise<{ items: ExtractionItem[] }> {
+  const response = await fetch(`${API_BASE}/tasks/${taskId}/items`);
+  
+  if (!response.ok) {
+    throw new Error(`Get task items failed: ${response.statusText}`);
+  }
+  
+  return await response.json();
+}
+
+/**
+ * 裁决冲突
+ */
+export async function resolveConflict(
+  itemId: string, 
+  fieldName: string, 
+  value: string
+): Promise<{ success: boolean }> {
+  const response = await fetch(`${API_BASE}/items/${itemId}/resolve`, {
+    method: 'POST',
+    headers: { 'Content-Type': 'application/json' },
+    body: JSON.stringify({ fieldName, chosenValue: value }),
+  });
+  
+  if (!response.ok) {
+    throw new Error(`Resolve conflict failed: ${response.statusText}`);
+  }
+  
+  return await response.json();
+}
+
+/**
+ * 导出结果
+ */
+export async function exportResults(taskId: string): Promise<Blob> {
+  const response = await fetch(`${API_BASE}/tasks/${taskId}/export`);
+  
+  if (!response.ok) {
+    throw new Error(`Export results failed: ${response.statusText}`);
+  }
+  
+  return await response.blob();
+}
+