fix(system): keep the server's search-again line on a duplicate review

A duplicate cleanup review the server refuses with 409 sources-changed
showed the generic "could not be reviewed" message; it now shows the
server's "The sources changed since the search. Search for duplicates
again."

tests/js/workspace-system-maintenance.test.js

@@ -93,6 +93,9 @@ test('a refused apply names its reason; a lost answer is not confirmed', async (
     assert.equal(reviewRefusal(error(413, 'too-large', 'This plan is too large to review at once.')),
         'This plan is too large to review at once.');
     assert.equal(reviewRefusal(error(500, null, 'boom')), REVIEW_FAILED);
+    // S7 re-review N1: a duplicate review whose sources changed since the search keeps the server's "search again".
+    const changed = 'The sources changed since the search. Search for duplicates again.';
+    assert.equal(reviewRefusal(error(409, 'sources-changed', changed)), changed);
     assert.equal(reviewRefusal(new TypeError('x')), REVIEW_FAILED);
 });
 

web/js/workspace/maintenance-review.mjs

@@ -56,7 +56,7 @@ export const OPERATION_TITLES = Object.freeze({
 const REVIEW_AGAIN = new Set(['plan-expired', 'storage-changed']);
 // Refusals whose server message is the whole truth.
 const SERVER_SAYS = new Set(['insufficient-space', 'nothing-to-do', 'too-large', 'invalid-request', 'not-found',
-    'job-running', 'no-groups', 'apply-failed']);
+    'job-running', 'no-groups', 'apply-failed', 'sources-changed']);
 
 const number = value => value.toLocaleString('en-US');