feat: complete authored pull workspace access (Closes #1348)

frontend/pull-sheet.js

@@ -187,17 +187,27 @@ function ownershipExitMessage(item, action, transitionResult) {
     '. Next work item opened.' : '. Choose the next ready Today item.');
 }
 
-function resetOwnershipControls(doc, item, checkpointed) {
+function applyOwnershipCapabilities(doc, capabilities = null) {
+  const ownership = doc.querySelector('#pull-ownership');
+  const assigned = capabilities?.assigned !== false;
+  ownership.hidden = !assigned;
+  ownership.inert = !assigned;
+  return assigned;
+}
+
+function resetOwnershipControls(doc, item, checkpointed, capabilities = null) {
   const qs = selector => doc.querySelector(selector);
+  const assigned = applyOwnershipCapabilities(doc, capabilities);
   qs('#pull-ownership').open = false;
   qs('#pull-handoff-recipient').innerHTML = '<option value="">Select a teammate</option>';
   qs('#pull-handoff-recipient').disabled = true;
   qs('#confirm-pull-handoff').disabled = true;
   qs('#confirm-pull-handoff').textContent = checkpointed(item) ? 'Hand off & next' : 'Confirm handoff';
-  qs('#load-pull-handoff').disabled = false;
-  qs('#release-pull').disabled = false;
+  qs('#load-pull-handoff').disabled = !assigned;
+  qs('#release-pull').disabled = !assigned;
   qs('#release-pull').textContent = checkpointed(item) ? 'Release & next' : 'Release assignment';
-  qs('#pull-handoff-status').textContent = 'Load teammates to transfer ownership.';
+  qs('#pull-handoff-status').textContent = assigned ?
+    'Load teammates to transfer ownership.' : 'Assignment controls are not available for this pull request.';
   qs('#edit-pull-content').hidden = true;
   qs('#pull-edit-form').hidden = true;
   qs('#pull-edit-status').textContent = '';
@@ -227,6 +237,7 @@ function bindReviewRequestControls(doc, controller, getSelected, getDetail, getL
   load.dataset.reviewRequestBound = 'true';
   controller.setReviewDetail = detail => {
     resetReviewRequestControls(doc, detail);
+    applyOwnershipCapabilities(doc, detail?.capabilities);
     controller.edit?.setDetail(detail, Boolean(detail?.saved_at));
     const publishable = detail?.state === 'open' && detail?.draft === true &&
       detail?.author === getLogin?.() && detail?.head_sha;