needs: also_moved_by - a need carried by more than one group's desk

Roles overlap on one aggregate: a project manager prices a change, a
site manager completes it. A need may list the other groups whose
desks hold some of its moves; their buttons count toward reaching
`done_when` and toward the strand check exactly as `handled_by`'s do.
`handled_by` must still hold a desk of its own, so that someone is
answerable for the record.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01L4jrCgLiKKHAEFuZUJjckH

src/needs.rs

@@ -86,6 +86,13 @@ pub struct Need {
     /// becoming open -> quoted) fails instead of passing.
     #[serde(default)]
     pub stages: Vec<String>,
+    /// Other groups whose desks carry some of this need's moves: a
+    /// site manager closing what a project manager opened. Their
+    /// buttons count toward reaching `done_when` exactly as
+    /// `handled_by`'s do. `handled_by` must still hold a desk of its
+    /// own - someone has to be answerable for the record.
+    #[serde(default)]
+    pub also_moved_by: Vec<String>,
 }
 
 fn root() -> String {
@@ -392,9 +399,11 @@ pub fn check(
         let desks = desks_over(questions, &need.lands_in);
         let own: Vec<&Desk> = desks
             .iter()
-            .filter(|d| d.group.as_deref() == Some(need.handled_by.as_str()))
+            .filter(|d| {
+                d.group.as_deref().is_some_and(|g| g == need.handled_by || need.also_moved_by.iter().any(|m| m == g))
+            })
             .collect();
-        if own.is_empty() {
+        if !desks.iter().any(|d| d.group.as_deref() == Some(need.handled_by.as_str())) {
             let others: Vec<String> = desks
                 .iter()
                 .map(|d| format!("{} ({})", d.page, d.group.as_deref().unwrap_or("ungated")))
@@ -883,6 +892,29 @@ mod tests {
         );
     }
 
+    #[test]
+    fn a_need_can_be_carried_by_more_than_one_groups_desk() {
+        // owners may only quote or lose; closing a quoted job is the
+        // site managers' button, on a desk of their own.
+        let (mut questions, aggregates) = site("            - { to: quoted, label: Quote }\n            - { to: lost, label: Lose }\n");
+        let more = build_questions(&[(
+            "site/index.yaml".to_string(),
+            "name: Site desk\nqualifies: site_managers\nalternatives:\n  - name: Projects\n    features:\n      - name: \"\"\n        resource:\n          source: { kind: kv, bucket: projects }\n          requires_group: site_managers\n          transitions:\n            - { from: quoted, to: won, label: Win }\n            - { from: quoted, to: lost, label: Lose }\n".to_string(),
+        )])
+        .unwrap();
+        questions.extend(more);
+
+        let mut file = needs("");
+        // Alone, owners cannot finish it...
+        assert_eq!(fails(&check(&file, &questions, &aggregates)).len(), 2);
+        // ...with the site managers' buttons counted, they can.
+        file.needs[0].also_moved_by = vec!["site_managers".to_string()];
+        assert!(check(&file, &questions, &aggregates).is_empty());
+        // But someone has to be answerable: handled_by needs its own desk.
+        file.needs[0].handled_by = "nobody".to_string();
+        assert!(fails(&check(&file, &questions, &aggregates))[0].starts_with("no desk gated on \"nobody\""));
+    }
+
     #[test]
     fn the_wrong_group_holding_the_desk_is_a_failure() {
         let (questions, aggregates) = site(FULL_DESK);