Dashboard: count the success and timeout stop reasons

[RoldSI]

Follow-up to #49, which is already merged. That PR added the "success" stop reason but missed one place that enumerates stop reasons, so main is currently dropping won tasks from the dashboard's outcomes chart.

buildOutcomes counts a task only when its stop_reason is a key of counts:

var counts = {done:0, max_runs:0, budget_exhausted:0, error:0};
tasks.forEach(function(t){
  if (Object.prototype.hasOwnProperty.call(counts, t.stop_reason)) counts[t.stop_reason]++;
  else if (t.status === "error") counts.error++;
});

Since #49, most won tasks stop for reason "success", which is not a key, so they fall through both branches and are counted nowhere. The chart's denominator is OUTCOME_DEFS.reduce(...) over the same keys, so the remaining segments silently renormalise to 100% and the omission is invisible.

"timeout" was missing too. That one predates #49: it has been a StopReason for a while, so the chart has been quietly dropping timed-out tasks all along.

Both added. The status-keyed views (breach / failure / error at lines 302, 456, 512) were already correct and are untouched; this is only the stop_reason-keyed chart.

594 passed. No Python changed.