fix(mobile): distinguish auth failure from HR mismatch on position sync page

问题:登录态失效(token 冻结/无效,后端返 401)时,同步岗位页把认证错误
误显示成「人力系统中未匹配到当前手机号的在职岗位,请联系 HR」,员工被
困在该页无路可退。

修复:
- api.ts: 新增 ApiError(statusCode/bizCode) 类型化错误与 isAuthApiError,
  readPayload/parsePayloadText/XHR 路径统一抛出带状态码的错误,消息不变
- position.ts: fetchOrgPositionResult 返回四态判别结果
  matched/unmatched/unauthorized/error;hydratePositionFromOrg 行为不变
- position/index.vue: 按四态分支处理——
  · unauthorized -> 清除登录态并自动回登录页(保留 redirect)
  · error -> 提示「网络异常…请重试」,保留重试按钮
  · unmatched -> 才显示联系 HR 文案
  并新增「退出重新登录」链接(确认弹窗后清登录态回登录页),
  避免任何异常场景下用户被困无退出路径

验证(构建产物 + 生产 API,Playwright 五场景全过,截图见
.data/visual-audit-20260718/position-fix/):
S1 固定码真实登录->今日页(保洁岗匹配) S2 无效token->自动回登录
S3 断网->网络异常提示留在本页 S4 有效token->自动通过
S5 退出链接->确认->回登录且登录态已清

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

mobile-uni/src/services/api.ts

@@ -15,6 +15,22 @@ export interface RequestOptions {
   clearAuthOnUnauthorized?: boolean;
 }
 
+export class ApiError extends Error {
+  readonly statusCode: number;
+  readonly bizCode?: number;
+
+  constructor(message: string, statusCode: number, bizCode?: number) {
+    super(message);
+    this.name = 'ApiError';
+    this.statusCode = statusCode;
+    this.bizCode = bizCode;
+  }
+}
+
+export const isAuthApiError = (error: unknown): boolean =>
+  error instanceof ApiError
+  && (error.statusCode === 401 || error.statusCode === 403 || error.bizCode === 401 || error.bizCode === 403);
+
 const normalizeUrl = (url: string) => `${apiBase}${url.startsWith('/') ? url : `/${url}`}`;
 
 export const apiUrl = normalizeUrl;
@@ -35,7 +51,7 @@ export const readPayload = <T>(statusCode: number, data: unknown, clearAuthOnUna
     if (clearAuthOnUnauthorized && (statusCode === 401 || statusCode === 403 || code === 401 || code === 403)) {
       clearAuth();
     }
-    throw new Error(payload?.msg || `HTTP ${statusCode}`);
+    throw new ApiError(payload?.msg || `HTTP ${statusCode}`, statusCode, code);
   }
 
   return payload?.data as T;
@@ -47,7 +63,7 @@ export const parsePayloadText = (statusCode: number, text: string, clearAuthOnUn
   } catch (error) {
     if (clearAuthOnUnauthorized && (statusCode === 401 || statusCode === 403)) clearAuth();
     throw error instanceof SyntaxError
-      ? new Error(statusCode >= 400 ? `HTTP ${statusCode}` : '响应解析失败')
+      ? new ApiError(statusCode >= 400 ? `HTTP ${statusCode}` : '响应解析失败', statusCode)
       : error;
   }
 };
@@ -72,8 +88,10 @@ const requestWithXhr = async <T>(options: RequestOptions): Promise<T> => {
           status: xhr.status,
           data: parsePayloadText(xhr.status, xhr.responseText || 'null', options.clearAuthOnUnauthorized !== false)
         });
-      } catch {
-        reject(new Error(xhr.status >= 400 ? `HTTP ${xhr.status}` : '响应解析失败'));
+      } catch (error) {
+        reject(error instanceof ApiError
+          ? error
+          : new Error(xhr.status >= 400 ? `HTTP ${xhr.status}` : '响应解析失败'));
       }
     };
     xhr.onerror = () => reject(new Error('网络请求失败'));