refactor(web): update API service, view script and add tests

Frontend:
- services/api.js: update API service client
- views/scripts/EmployeeManagementView.js: update employee management view script
- tests/api-request.test.mjs: update API request tests

Scripts:
- create_employee.sh: add employee creation script

web/tests/api-request.test.mjs

@@ -45,7 +45,7 @@ async function testSupportsBlobResponses() {
   assert.equal(payload, blob)
 }
 
-async function testInjectsAuthenticatedUserHeaders() {
+async function testInjectsAuthenticatedUserHeaders() {
   const sessionStorage = new Map([
     [
       'x-financial-auth-user',
@@ -82,16 +82,48 @@ async function testInjectsAuthenticatedUserHeaders() {
 
   assert.equal(capturedOptions.headers['x-auth-username'], 'admin')
   assert.equal(capturedOptions.headers['x-auth-name'], '系统管理员')
-  assert.equal(capturedOptions.headers['x-auth-role-codes'], 'manager')
-  assert.equal(capturedOptions.headers['x-auth-is-admin'], 'true')
-}
-
-async function run() {
-  await testUsesCustomContentTypeHeader()
-  await testSupportsBlobResponses()
-  await testInjectsAuthenticatedUserHeaders()
-  console.log('api-request tests passed')
-}
+  assert.equal(capturedOptions.headers['x-auth-role-codes'], 'manager')
+  assert.equal(capturedOptions.headers['x-auth-is-admin'], 'true')
+}
+
+async function testFormatsValidationErrors() {
+  global.fetch = async () => ({
+    ok: false,
+    async json() {
+      return {
+        detail: [
+          {
+            loc: ['body', 'email'],
+            msg: 'value is not a valid email address'
+          },
+          {
+            loc: ['body', 'password'],
+            msg: 'String should have at least 5 characters'
+          }
+        ]
+      }
+    }
+  })
+
+  await assert.rejects(
+    () => apiRequest('/employees/demo', { method: 'PATCH', body: '{}' }),
+    (error) => {
+      assert.equal(
+        error.message,
+        'email: value is not a valid email address；password: String should have at least 5 characters'
+      )
+      return true
+    }
+  )
+}
+
+async function run() {
+  await testUsesCustomContentTypeHeader()
+  await testSupportsBlobResponses()
+  await testInjectsAuthenticatedUserHeaders()
+  await testFormatsValidationErrors()
+  console.log('api-request tests passed')
+}
 
 run().catch((error) => {
   console.error(error)