feat(plugin): P1-P4 审计修复 — 第一批 (Excel/CSV导出 + 市场API + 对账扫描)

1.1 Excel/CSV 导出:
- 后端 export 支持 format 参数 (json/csv/xlsx)
- rust_xlsxwriter 生成带样式 Excel
- 前端导出按钮改为 Dropdown 格式选择 (JSON/CSV/Excel)
- blob 下载支持 CSV/XLSX 二进制格式

1.2 市场后端 API + 前端对接:
- SeaORM Entity: market_entry, market_review
- API: 浏览/详情/一键安装/评论列表/提交评分
- 一键安装: upload → install → enable 一条龙 + 依赖检查
- 前端 PluginMarket 对接真实 API (搜索/分类/安装/评分)

1.3 对账扫描:
- reconcile_references() 扫描跨插件引用悬空 UUID
- POST /plugins/{plugin_id}/reconcile 端点

crates/erp-plugin/src/data_dto.rs

@@ -178,10 +178,17 @@ pub struct ExportParams {
     pub sort_by: Option<String>,
     /// "asc" or "desc"
     pub sort_order: Option<String>,
-    /// 导出格式: "csv" (默认) | "json"
+    /// 导出格式: "json" (默认) | "csv" | "xlsx"
     pub format: Option<String>,
 }
 
+/// 导出结果 — 根据格式返回不同内容
+pub enum ExportPayload {
+    Json(Vec<serde_json::Value>),
+    Csv(Vec<u8>),
+    Xlsx(Vec<u8>),
+}
+
 /// 数据导入请求
 #[derive(Debug, Serialize, Deserialize, utoipa::ToSchema)]
 pub struct ImportReq {
@@ -209,3 +216,92 @@ pub struct ImportRowError {
     /// 错误消息列表
     pub errors: Vec<String>,
 }
+
+// ─── 市场目录 DTO ──────────────────────────────────────────────────
+
+/// 市场条目列表查询参数
+#[derive(Debug, Serialize, Deserialize, utoipa::IntoParams)]
+pub struct MarketListParams {
+    pub page: Option<u64>,
+    pub page_size: Option<u64>,
+    pub category: Option<String>,
+    pub search: Option<String>,
+}
+
+/// 市场条目响应（不含二进制数据）
+#[derive(Debug, Serialize, Deserialize, utoipa::ToSchema)]
+pub struct MarketEntryResp {
+    pub id: String,
+    pub plugin_id: String,
+    pub name: String,
+    pub version: String,
+    pub description: Option<String>,
+    pub author: Option<String>,
+    pub category: Option<String>,
+    pub tags: Option<serde_json::Value>,
+    pub icon_url: Option<String>,
+    pub screenshots: Option<serde_json::Value>,
+    pub min_platform_version: Option<String>,
+    pub status: String,
+    pub download_count: i32,
+    pub rating_avg: f64,
+    pub rating_count: i32,
+    pub changelog: Option<String>,
+    pub created_at: Option<chrono::DateTime<chrono::Utc>>,
+    pub updated_at: Option<chrono::DateTime<chrono::Utc>>,
+}
+
+/// 市场条目详情响应（含完整信息）
+#[derive(Debug, Serialize, Deserialize, utoipa::ToSchema)]
+pub struct MarketEntryDetailResp {
+    #[serde(flatten)]
+    pub entry: MarketEntryResp,
+    /// 依赖提示（安装时检查 manifest.dependencies）
+    pub dependency_warnings: Vec<String>,
+}
+
+/// 提交评分/评论请求
+#[derive(Debug, Serialize, Deserialize, utoipa::ToSchema)]
+pub struct SubmitReviewReq {
+    /// 评分 1-5
+    pub rating: i32,
+    /// 评论内容
+    pub review_text: Option<String>,
+}
+
+/// 评论响应
+#[derive(Debug, Serialize, Deserialize, utoipa::ToSchema)]
+pub struct MarketReviewResp {
+    pub id: String,
+    pub user_id: String,
+    pub market_entry_id: String,
+    pub rating: i32,
+    pub review_text: Option<String>,
+    pub created_at: Option<chrono::DateTime<chrono::Utc>>,
+}
+
+// ─── 对账扫描 DTO ──────────────────────────────────────────────────
+
+/// 对账报告
+#[derive(Debug, Serialize, Deserialize, utoipa::ToSchema)]
+pub struct ReconciliationReport {
+    /// 有效引用数
+    pub valid_count: i64,
+    /// 悬空引用数
+    pub dangling_count: i64,
+    /// 悬空引用详情
+    pub details: Vec<DanglingRef>,
+}
+
+/// 悬空引用详情
+#[derive(Debug, Serialize, Deserialize, utoipa::ToSchema)]
+pub struct DanglingRef {
+    /// 实体名
+    pub entity: String,
+    /// 字段名
+    pub field: String,
+    /// 记录 ID
+    pub record_id: String,
+    /// 悬空的 UUID 值
+    pub dangling_value: String,
+}