feat: simplify Sense password policy (#42)

Sense/ui/src/views/sense/identity/Users.vue

@@ -30,7 +30,7 @@
         <el-form-item label="用户名" prop="username"><el-input v-model="form.username" :disabled="Boolean(editingID)" /></el-form-item>
         <el-form-item label="姓名" prop="display_name"><el-input v-model="form.display_name" /></el-form-item>
         <el-form-item label="角色" prop="role"><el-select v-model="form.role" style="width: 100%"><el-option v-for="role in roles" :key="role.value" :label="role.label" :value="role.value" /></el-select></el-form-item>
-        <el-form-item v-if="!editingID" label="初始密码" prop="password"><el-input v-model="form.password" type="password" show-password /><div class="field-hint">至少 6 位，包含大小写字母和数字，且不含用户名。</div></el-form-item>
+        <el-form-item v-if="!editingID" label="初始密码" prop="password"><el-input v-model="form.password" type="password" show-password /><div class="field-hint">至少 6 位字符。</div></el-form-item>
         <el-form-item v-else label="状态"><el-switch v-model="form.enabled" active-text="启用" inactive-text="停用" /></el-form-item>
       </el-form>
       <template #footer><el-button @click="dialogVisible = false">取消</el-button><el-button type="primary" :loading="saving" @click="save">保存</el-button></template>