feat: 上线前安全加固与发布工程化；appmall 由插件迁移为独立应用

安全（P0）
- 发布包签名：新增 scripts/package_keygen.php、scripts/package_verify.php、
  ywxapp\service\PackageVerifier；FrameworkService::apply() 解压前强制验签
  （ywxapp.framework_package_verify，默认开启）
- JWT 收紧：config/jwt.php 移除公开默认密钥，JwtService::assertStrongSecret()
  校验非空 / 长度≥32 / 已知弱值；.env.production.example 键名由 JWT_SECRET_KEY 修正为 JWT_SECRET
- /api/v1/Article：免登录白名单收窄为只读接口，写操作字段白名单 + assertOwner() 越权校验
- 开发者令牌：查找接口不再回显明文、统一失败文案 + 限流
- TemplateInstaller：文件名白名单 + realpath 归一化 + 目录内断言，修复 Zip Slip；补 use ZipArchive
- 后台登录：接入验证码、失败锁定与登录限流（config/ratelimit.php）
- 缓存 / Session 驱动可由 .env 覆盖（CACHE_DRIVER / SESSION_TYPE），集群部署改 redis
- paycenter 支付日志开关改为 PAY_LOG，不再跟随 APP_DEBUG

工程化 / 交付
- 新增 CHANGELOG.md 与 .env.production.example；composer.lock 入库锁定依赖版本
- 插件离线安装 CLI 增加 --uid，后台上传安装透传 uid，付费插件授权校验可通过
- 授权拒绝文案区分「未携带 uid」与「未找到有效授权」，便于排障
- .gitignore 放行 .env.production.example / .env.addon.example / .gitattributes / public/.htaccess

结构
- appmall 由 addon/appmall 迁移为独立应用 app/appmall（市场 / 开发者中心 / 审核 / 分润）

addon/articles/view/backend/topic/edit.html

@@ -0,0 +1,94 @@
+<div class="layui-fluid">
+  <div class="layui-card">
+    <div class="layui-card-header">
+      {if $topic}编辑专题{else/}新建专题{/if}
+      <a href="{:url('articles/backend/topic/index')}" class="layui-btn layui-btn-sm layui-btn-primary" style="float:right;margin-top:6px;">返回</a>
+    </div>
+    <div class="layui-card-body">
+      <form class="layui-form">
+        <input type="hidden" name="id" value="{$topic.id|default='0'}">
+
+        <div class="layui-form-item">
+          <label class="layui-form-label">专题名称</label>
+          <div class="layui-input-block">
+            <input type="text" name="title" value="{$topic.title|default=''}" required lay-verify="required" class="layui-input" placeholder="如：新手入门">
+          </div>
+        </div>
+
+        <div class="layui-form-item">
+          <label class="layui-form-label">别名</label>
+          <div class="layui-input-block">
+            <input type="text" name="alias" value="{$topic.alias|default=''}" required lay-verify="required" class="layui-input" placeholder="URL 标识，如 getting-started">
+          </div>
+        </div>
+
+        <div class="layui-form-item">
+          <label class="layui-form-label">描述</label>
+          <div class="layui-input-block">
+            <textarea name="description" class="layui-textarea" placeholder="专题简介（用于聚合页 SEO description）">{$topic.description|default=''}</textarea>
+          </div>
+        </div>
+
+        <div class="layui-form-item">
+          <label class="layui-form-label">封面图</label>
+          <div class="layui-input-block">
+            <input type="text" name="cover" value="{$topic.cover|default=''}" class="layui-input" placeholder="图片地址">
+          </div>
+        </div>
+
+        <div class="layui-form-item">
+          <label class="layui-form-label">包含文章</label>
+          <div class="layui-input-block">
+            <input type="text" name="article_ids" id="article_ids" class="layui-input"
+                   value="{if isset($picked) && $picked}{:implode(',', array_column($picked, 'id'))}{/if}"
+                   placeholder="文章ID，逗号分隔；顺序即专题内展示顺序">
+            <div style="margin-top:8px;color:#666;">
+              {volist name='picked' id='p'}
+              <span class="layui-badge layui-bg-gray">#{$p.id} {$p.title}</span>
+              {/volist}
+              {empty name='picked'}
+              <span style="color:#999;">尚未选择文章（可在文章列表查看 ID）</span>
+              {/empty}
+            </div>
+          </div>
+        </div>
+
+        <div class="layui-form-item">
+          <label class="layui-form-label">排序</label>
+          <div class="layui-input-inline">
+            <input type="number" name="sort" value="{$topic.sort|default='0'}" class="layui-input">
+          </div>
+          <div class="layui-form-mid">越大越靠前</div>
+        </div>
+
+        <div class="layui-form-item">
+          <label class="layui-form-label">状态</label>
+          <div class="layui-input-inline">
+            <input type="checkbox" name="status" value="1" {if isset($topic['status']) ? $topic['status'] : 1}checked{/if} title="启用" lay-skin="switch">
+          </div>
+        </div>
+
+        <div class="layui-form-item">
+          <div class="layui-input-block">
+            <button class="layui-btn" lay-submit lay-filter="save">保存</button>
+            <a href="{:url('articles/backend/topic/index')}" class="layui-btn layui-btn-primary">返回</a>
+          </div>
+        </div>
+      </form>
+    </div>
+  </div>
+</div>
+
+<script>
+layui.use(['form', 'http', 'ywxapp'], function () {
+  var http = layui.http;
+  var form = layui.form;
+  form.on('submit(save)', function (data) {
+    http.post("{:url('articles/backend/topic/update')}", data.field).then(function (r) {
+        layer.msg(r.msg);
+        if (r.code) { setTimeout(function () { location.href = r.url || "{:url('articles/backend/topic/index')}"; }, 800); }
+      });
+    return false;
+  });
+});
+</script>

addon/articles/view/backend/topic/index.html

@@ -0,0 +1,53 @@
+<div class="layui-fluid">
+  <div class="layui-card">
+    <div class="layui-card-header">
+      专题管理
+      <a href="{:url('articles/backend/topic/save')}" class="layui-btn layui-btn-sm layui-btn-normal" style="float:right;margin-top:6px;">新建专题</a>
+    </div>
+    <div class="layui-card-body">
+      <table class="layui-table" id="table" lay-filter="table"></table>
+    </div>
+  </div>
+</div>
+
+<script type="text/html" id="toolbar">
+  <a class="layui-btn layui-btn-xs" lay-event="edit">编辑</a>
+  <a class="layui-btn layui-btn-xs layui-btn-danger" lay-event="del">删除</a>
+</script>
+
+<script>
+layui.use(['table', 'jquery', 'http', 'ywxapp'], function () {
+  var http = layui.http;
+  var table = layui.table, $ = layui.jquery;
+
+  var tableIns = table.render({
+    elem: '#table',
+    url: "{:url('articles/backend/topic/index')}",
+    method: 'post',
+    page: true,
+    cols: [[
+      { field: 'id', title: 'ID', width: 70 },
+      { field: 'title', title: '专题名称', minWidth: 180 },
+      { field: 'alias', title: '别名', width: 140 },
+      { field: 'article_count', title: '文章数', width: 90 },
+      { field: 'sort', title: '排序', width: 80 },
+      { field: 'status', title: '状态', width: 80, templet: function (d) { return d.status ? '<span class="layui-badge layui-bg-green">启用</span>' : '<span class="layui-badge">禁用</span>'; } },
+      { field: 'create_at', title: '创建时间', width: 170 },
+      { title: '操作', width: 140, toolbar: '#toolbar' }
+    ]]
+  });
+
+  table.on('tool(table)', function (obj) {
+    if (obj.event === 'edit') {
+      location.href = obj.data.edit_url;
+    } else if (obj.event === 'del') {
+      layer.confirm('确认删除该专题？（不会删除文章本身）', function () {
+        http.post("{:url('articles/backend/topic/delete')}", { id: obj.data.id }).then(function (r) {
+          layer.msg(r.msg);
+          if (r.code) { obj.del(); }
+        });
+      });
+    }
+  });
+});
+</script>