test: verify source response after unmount and retain narrowed source

tests/test_optimization_source.cjs

@@ -89,6 +89,7 @@ async function main(){
  let resolveStale;f.setReply(()=>new Promise(resolve=>resolveStale=resolve));const stale=f.tool('one').props.onClick();f.setReply(()=>({...sourceBody,source:'two() { :; }'}));await f.tool('two').props.onClick();f.render();resolveStale({http:404,body:{error:'Function not found in available scripts'}});await stale;f.render();assert.ok(text(f.dialog()).includes('Demo two'));assert.equal(flatten(f.dialog()).some(node=>node.props?.role==='alert'),false)
  const before=f.calls.length;f.escape();f.render();assert.equal(f.dialog(),undefined);assert.equal(f.calls.length,before)
  f.setReply(()=>sourceBody);await f.tool('one').props.onClick();f.render();let copyResolve;f.clipboard.writeText=()=>new Promise(resolve=>copyResolve=resolve);const copying=flatten(f.dialog()).find(node=>node.props?.title===f.t('actions.copyToClipboard')).props.onClick();f.close();f.render();copyResolve();await copying;f.render();assert.equal(f.dialog(),undefined)
+ let unmountedResolve;f.setReply(()=>new Promise(resolve=>unmountedResolve=resolve));const unmounted=f.tool('one').props.onClick();f.render();const snapshot=text(f.tree());f.unmount();unmountedResolve(sourceBody);await unmounted;f.render();assert.equal(text(f.tree()),snapshot,'response after unmount cannot update modal state')
  assert.equal(f.calls.filter(call=>call.method!=='GET').length,0);assert.equal(f.calls.filter(call=>/scan|update|script-runner/.test(call.endpoint)).length,0)
  console.log('PASS source viewer: actual Settings/fetchApi, EN/SK/fallback, 404/500/network/malformed/empty, exact copy, late requests and close/Esc; mutations/scan/update 0')
 }