worker: track work as natural task steps

crates/tui/src/app.rs

@@ -3539,7 +3539,9 @@ mod completion_flow_tests {
                 arguments: args.into(),
             });
         }
-        assert!(app.task_store.tasks().is_empty());
+        let tasks = app.task_store.tasks();
+        assert_eq!(tasks.len(), 1);
+        assert_eq!(tasks[0].status, crate::task::TaskStatus::Completed);
     }
 
     #[test]

crates/tui/src/task.rs

@@ -28,8 +28,8 @@ pub enum TaskStatus {
 }
 
 impl TaskStatus {
-    fn is_active(self) -> bool {
-        matches!(self, Self::Pending | Self::Inprogress)
+    fn is_retained(self) -> bool {
+        !matches!(self, Self::Deleted)
     }
 }
 
@@ -125,7 +125,7 @@ impl TaskStore {
                     if let Some(d) = p.description {
                         t.description = d;
                     }
-                    if !t.status.is_active() {
+                    if !t.status.is_retained() {
                         self.tasks.remove(task_position);
                     }
                 }
@@ -145,7 +145,7 @@ impl TaskStore {
     fn replace_with(&mut self, tasks: Vec<TaskEntry>) {
         let tasks: Vec<_> = tasks
             .into_iter()
-            .filter(|task| task.status.is_active())
+            .filter(|task| task.status.is_retained())
             .collect();
         self.next_taskid = tasks
             .iter()
@@ -194,7 +194,7 @@ fn parse_snapshot_text(text: &str) -> Option<Vec<TaskEntry>> {
         snapshot
             .tasks
             .into_iter()
-            .filter(|task| task.status.is_active())
+            .filter(|task| task.status.is_retained())
             .collect(),
     )
 }
@@ -241,7 +241,7 @@ mod tests {
     }
 
     #[test]
-    fn counts_tracks_only_active_tasks_after_completion() {
+    fn counts_retains_completed_tasks_until_deleted() {
         let mut s = TaskStore::new();
         s.apply_tool_call("TaskCreate", r#"{"subject":"a","description":""}"#);
         s.apply_tool_call("TaskCreate", r#"{"subject":"b","description":""}"#);
@@ -251,10 +251,13 @@ mod tests {
         let c = s.counts();
         assert_eq!(c.pending, 1);
         assert_eq!(c.inprogress, 1);
-        assert_eq!(c.completed, 0);
+        assert_eq!(c.completed, 1);
         assert_eq!(c.deleted, 0);
-        assert_eq!(c.total(), 2);
+        assert_eq!(c.total(), 3);
         assert_eq!(c.active(), 2);
+
+        s.apply_tool_call("TaskUpdate", r#"{"taskid":2,"status":"deleted"}"#);
+        assert!(s.tasks().iter().all(|task| task.taskid != 2));
     }
 
     /// Snapshot text matches the wrapping `Worker::try_pre_run_compact` and the
@@ -263,7 +266,7 @@ mod tests {
     fn wrap_snapshot(json_body: &str, overview: &str) -> String {
         format!(
             "[Session TaskStore snapshot]\n\n{overview}\n\n```json\n{json_body}\n```\n\n\
-             This is the active session task list preserved across compaction. \
+             This is the retained session task list preserved across compaction. \
              The following TaskList tool result presents the same state through the tool lane."
         )
     }
@@ -288,19 +291,21 @@ mod tests {
 }"#;
         let text = wrap_snapshot(
             body,
-            "TaskStore: 1 active task(s) (pending: 1, inprogress: 0)",
+            "TaskStore: 2 task(s) (pending: 1, inprogress: 0, completed: 1)",
         );
         let mut s = TaskStore::new();
         s.apply_tool_call("TaskCreate", r#"{"subject":"stale","description":""}"#);
         s.apply_system_message_text(&text);
         let tasks = s.tasks();
-        assert_eq!(tasks.len(), 1);
-        assert_eq!(tasks[0].taskid, 7);
-        assert_eq!(tasks[0].status, TaskStatus::Pending);
-        // Subsequent TaskCreate must continue beyond the highest active taskid
+        assert_eq!(tasks.len(), 2);
+        assert_eq!(tasks[0].taskid, 5);
+        assert_eq!(tasks[0].status, TaskStatus::Completed);
+        assert_eq!(tasks[1].taskid, 7);
+        assert_eq!(tasks[1].status, TaskStatus::Pending);
+        // Subsequent TaskCreate must continue beyond the highest retained taskid
         // observed in the snapshot.
         s.apply_tool_call("TaskCreate", r#"{"subject":"new","description":""}"#);
-        assert_eq!(s.tasks()[1].taskid, 8);
+        assert_eq!(s.tasks()[2].taskid, 8);
     }
 
     #[test]
@@ -324,7 +329,7 @@ mod tests {
     }
   ]
 }"#;
-        let text = wrap_snapshot(body, "TaskStore: 1 active task(s)");
+        let text = wrap_snapshot(body, "TaskStore: 1 task(s)");
         let mut s = TaskStore::new();
         s.apply_system_message_text(&text);
         let t = &s.tasks()[0];
@@ -349,13 +354,13 @@ mod snapshot_format_contract {
     fn wrap_pod_style(snapshot_text: &str) -> String {
         format!(
             "[Session TaskStore snapshot]\n\n{snapshot_text}\n\n\
-             This is the active session task list preserved across compaction. \
+             This is the retained session task list preserved across compaction. \
              The following TaskList tool result presents the same state through the tool lane."
         )
     }
 
     fn snapshot_fixture() -> &'static str {
-        r#"TaskStore: 1 active task(s) (pending: 0, inprogress: 1)
+        r#"TaskStore: 1 task(s) (pending: 0, inprogress: 1, completed: 0)
 
 ```json
 {
@@ -372,7 +377,7 @@ mod snapshot_format_contract {
     }
 
     fn empty_snapshot_fixture() -> &'static str {
-        r#"TaskStore: 0 active task(s) (pending: 0, inprogress: 0)
+        r#"TaskStore: 0 task(s) (pending: 0, inprogress: 0, completed: 0)
 
 ```json
 {