fix: broadcast k6 stdout summary and show full stats

- Remove --out json=- (was flooding stdout and hiding summary)
- Broadcast both stdout (summary table) and stderr (live warnings)
- Add --summary-trend-stats with p(90)/p(95)/p(99)
- Parse checks, failed count/total, data received, all percentiles
- Strip ANSI codes before regex matching
- Add threshold pass/fail banner with per-threshold status
- Show all duration percentiles as individual cards

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend/server.js

@@ -132,7 +132,11 @@ app.post('/api/tests', (req, res) => {
   const clients = new Set();
   activeTests[id] = { clients };
 
-  const k6 = spawn('k6', ['run', '--out', 'json=-', tmpScript]);
+  const k6 = spawn('k6', [
+    'run',
+    '--summary-trend-stats', 'avg,min,med,max,p(90),p(95),p(99)',
+    tmpScript,
+  ]);
 
   const broadcast = (data) => {
     outputBuffer += data;
@@ -141,14 +145,11 @@ app.post('/api/tests', (req, res) => {
     }
   };
 
-  k6.stdout.on('data', (data) => {
-    // k6 JSON metrics go to stdout when using --out json=-
-    // We collect but don't broadcast raw JSON (it's noisy)
-  });
+  // stdout = final summary table (the important part)
+  k6.stdout.on('data', (data) => broadcast(data.toString()));
 
-  k6.stderr.on('data', (data) => {
-    broadcast(data.toString());
-  });
+  // stderr = live progress bars + warnings
+  k6.stderr.on('data', (data) => broadcast(data.toString()));
 
   k6.on('close', (code) => {
     fs.unlink(tmpScript, () => {});
@@ -226,19 +227,33 @@ app.delete('/api/tests/:id', (req, res) => {
 
 // Parse k6 terminal output for key metrics
 function parseSummary(output) {
+  // Strip ANSI colour codes before matching
+  const plain = output.replace(/\x1b\[[0-9;]*m/g, '');
   const summary = {};
+
   const patterns = {
-    http_reqs:         /http_reqs\.*\s+([\d.]+)\s+([\d.]+\/s)/,
-    http_req_duration: /http_req_duration\.*\s+avg=([\d.]+\w+)\s+min=([\d.]+\w+)\s+med=([\d.]+\w+)\s+max=([\d.]+\w+)\s+p\(90\)=([\d.]+\w+)\s+p\(95\)=([\d.]+\w+)/,
-    http_req_failed:   /http_req_failed\.*\s+([\d.]+%)/,
-    vus:               /vus\.*\s+(\d+)\s+min=(\d+)\s+max=(\d+)/,
-    iterations:        /iterations\.*\s+([\d.]+)\s+([\d.]+\/s)/,
+    http_reqs:         /http_reqs[\s.]+(\d+)\s+([\d.]+\/s)/,
+    http_req_duration: /http_req_duration[\s.]+avg=([\d.µms]+)\s+min=([\d.µms]+)\s+med=([\d.µms]+)\s+max=([\d.µms]+)\s+p\(90\)=([\d.µms]+)\s+p\(95\)=([\d.µms]+)\s+p\(99\)=([\d.µms]+)/,
+    http_req_failed:   /http_req_failed[\s.]+(\d+\.?\d*%)\s+(\d+) out of (\d+)/,
+    checks:            /checks[\s.]+(\d+\.?\d*%)\s+(\d+) out of (\d+)/,
+    iterations:        /iterations[\s.]+(\d+)\s+([\d.]+\/s)/,
+    vus:               /vus[\s.]+(\d+)\s+min=(\d+)\s+max=(\d+)/,
+    data_received:     /data_received[\s.]+([\d.]+ \w+)\s+([\d.]+ \w+\/s)/,
+    data_sent:         /data_sent[\s.]+([\d.]+ \w+)\s+([\d.]+ \w+\/s)/,
   };
 
   for (const [key, re] of Object.entries(patterns)) {
-    const m = output.match(re);
+    const m = plain.match(re);
     if (m) summary[key] = m.slice(1);
   }
+
+  // Extract threshold results (✓ / ✗ lines)
+  const thresholds = [];
+  for (const m of plain.matchAll(/(✓|✗)\s+(.+)/g)) {
+    thresholds.push({ pass: m[1] === '✓', label: m[2].trim() });
+  }
+  if (thresholds.length) summary.thresholds = thresholds;
+
   return summary;
 }