fix(delivery/mcp): 补 get_delivery_status 经 scoped dispatch 转发 pr_number/branch 的回归测试（P3-F 审查）

使者回传 #203 的症状是「传 pr_number 也不起作用」，但原有 MCP 层测试只覆盖非法参数报错，
dispatch 若丢弃已解析的查询目标、改传默认值，全部测试仍通过。新增 scoped dispatch 正向测试，
断言 pr_number/branch/null 分别得到 pull_request/branch/local_branch 目标；已用变异
（dispatch 改传 DeliveryQuery::default()）确认该测试会失败。

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src-tauri/src/mcp_tools.rs

@@ -2680,6 +2680,67 @@ mod tests {
         assert!(text.contains("feat/delivery-status-by-pr"), "{text}");
     }
 
+    /// 使者回传 #203 的症状正是「传 pr_number 也不起作用」：经 scoped dispatch 断言
+    /// pr_number/branch 真正到达能力本体（未绑定 Gitea，不发网络请求）。
+    #[tokio::test]
+    async fn delivery_status_dispatch_forwards_pr_and_branch_targets() {
+        db::init_test_pool();
+        let base = temp_base("delivery_target_dispatch");
+        {
+            let conn = db::pool().get().unwrap();
+            conn.execute(
+                "INSERT OR IGNORE INTO project_profiles (id, name) VALUES ('delivery-target-profile', 'Delivery target fixture')",
+                [],
+            )
+            .unwrap();
+            conn.execute(
+                "INSERT OR IGNORE INTO project_workspaces (id, profile_id, win_path) VALUES ('delivery-target', 'delivery-target-profile', ?1)",
+                [base.to_str().unwrap()],
+            )
+            .unwrap();
+        }
+        let target_of = |result: &Value| {
+            assert_ne!(result["isError"], true, "{result}");
+            result["structuredContent"]["target"].clone()
+        };
+
+        let by_pr = tools_call_for_project(
+            Some(&json!({"name": "get_delivery_status", "arguments": {
+                "pr_number": 31, "branch": "feat/worktree"
+            }})),
+            "delivery-target",
+        )
+        .await;
+        let target = target_of(&by_pr);
+        assert_eq!(target["mode"], "pull_request", "{by_pr}");
+        assert_eq!(target["pr_number"], 31, "{by_pr}");
+        assert_eq!(
+            by_pr["structuredContent"]["pull_request"]["state"],
+            "not_configured"
+        );
+
+        let by_branch = tools_call_for_project(
+            Some(&json!({"name": "get_delivery_status", "arguments": {
+                "branch": "feat/worktree"
+            }})),
+            "delivery-target",
+        )
+        .await;
+        let target = target_of(&by_branch);
+        assert_eq!(target["mode"], "branch", "{by_branch}");
+        assert_eq!(target["branch"], "feat/worktree", "{by_branch}");
+
+        let default = tools_call_for_project(
+            Some(&json!({"name": "get_delivery_status", "arguments": {
+                "pr_number": null, "branch": null
+            }})),
+            "delivery-target",
+        )
+        .await;
+        assert_eq!(target_of(&default)["mode"], "local_branch", "{default}");
+        let _ = std::fs::remove_dir_all(&base);
+    }
+
     #[tokio::test]
     async fn delivery_status_tool_requires_project_id() {
         let result = tools_call(Some(&json!({