fix: 7 项 E2E Bug 修复 — Dashboard 404 / 记忆去重 / 记忆注入 / invoice_id / Prompt 版本

P0:
- BUG-H1: Dashboard 路由 /api/v1/stats/dashboard → /api/v1/admin/dashboard

P1:
- BUG-H2: viking_add 预检查 content_hash 去重，返回 "deduped" 状态；SqliteStorage 启动时回填已有条目 content_hash
- BUG-M5: saas-relay-client 发送前调用 viking_inject_prompt 注入跨会话记忆

P2:
- BUG-M1: PaymentResult 添加 invoice_id 字段，query_payment_status 返回 invoice_id
- BUG-M2: UpdatePromptRequest 添加内容字段，更新时自动创建新版本并递增 current_version
- BUG-M3: viking_find scope 参数文档化（设计行为，调用方需传 agent scope）
- BUG-M4: Dashboard 路由缺失已修复，handler 层 require_admin 已正确返回 403

P3 (确认已修复/非代码问题):
- BUG-L1: pain_seed_categories 已统一，无 pain_seeds 残留
- BUG-L2: pipeline_create 参数格式正确，E2E 测试方法问题

crates/zclaw-saas/src/billing/payment.rs

@@ -101,6 +101,7 @@ pub async fn create_payment(
 
     Ok(PaymentResult {
         payment_id,
+        invoice_id,
         trade_no,
         pay_url,
         amount_cents: plan.price_cents,
@@ -272,8 +273,8 @@ pub async fn query_payment_status(
     payment_id: &str,
     account_id: &str,
 ) -> SaasResult<serde_json::Value> {
-    let payment: (String, String, i32, String, String) = sqlx::query_as::<_, (String, String, i32, String, String)>(
-        "SELECT id, method, amount_cents, currency, status \
+    let payment: (String, String, String, i32, String, String) = sqlx::query_as::<_, (String, String, String, i32, String, String)>(
+        "SELECT id, invoice_id, method, amount_cents, currency, status \
          FROM billing_payments WHERE id = $1 AND account_id = $2"
     )
     .bind(payment_id)
@@ -282,9 +283,10 @@ pub async fn query_payment_status(
     .await?
     .ok_or_else(|| SaasError::NotFound("支付记录不存在".into()))?;
 
-    let (id, method, amount, currency, status) = payment;
+    let (id, invoice_id, method, amount, currency, status) = payment;
     Ok(serde_json::json!({
         "id": id,
+        "invoice_id": invoice_id,
         "method": method,
         "amount_cents": amount,
         "currency": currency,