feat: show update download telemetry

Calculate download throughput and remaining time from verified installer bytes and display downloaded size, total size, speed, and ETA beneath the progress track while retaining the last values after cancellation.

tests/startup-renderer.test.js

@@ -176,4 +176,5 @@ test('header occupies its final geometry before asynchronous initialization', ()
   assert.match(css, /\.header-update-button\.update-available:hover\s*\{[^}]*background:\s*var\(--success-end\);[^}]*color:\s*#000;/su);
   assert.match(css, /\.update-dialog\s*\{[^}]*width:\s*min\(576px,\s*100%\);/su);
   assert.match(css, /\.update-release-notes\s*\{[^}]*height:\s*min\(220px,\s*42vh\);/su);
+  assert.match(html, /class="update-progress-footer"[\s\S]*id="updateProgressDetails"[\s\S]*id="updateProgressText"/u);
 });

tests/ui-smoke.js

@@ -2460,7 +2460,7 @@ setTimeout(async () => {
 
     const busyUpdateState = await wc.executeJavaScript(\`(() => {
       showUpdateBanner({ remoteVersion: '9.9.9' });
-      handleUpdateProgress({ stage: 'downloading', percent: 50 });
+      handleUpdateProgress({ stage: 'downloading', percent: 50, bytesDownloaded: 40 * 1024 * 1024, bytesTotal: 100 * 1024 * 1024, bytesPerSecond: 8 * 1024 * 1024, etaSeconds: 8 });
       const overlay = document.getElementById('updateBanner');
       document.getElementById('updateCloseBtn').click();
       document.getElementById('dismissUpdateBtn').click();
@@ -2480,6 +2480,7 @@ setTimeout(async () => {
         messageText: document.getElementById('updateMessage').textContent,
         progressLabel: progress.getAttribute('aria-label'),
         progressText: progress.getAttribute('aria-valuetext'),
+        progressDetails: document.getElementById('updateProgressDetails').textContent,
         progressState: progress.dataset.state,
         progressColor: getComputedStyle(progress).backgroundColor,
         progressTrackWidth: progress.parentElement.getBoundingClientRect().width,
@@ -2489,6 +2490,7 @@ setTimeout(async () => {
     })()\`);
     check('Busy update keeps its progress dialog open with a dangerous download cancellation action', busyUpdateState.display === 'flex' && busyUpdateState.hidden === 'false' && busyUpdateState.closeDisabled === true && busyUpdateState.dismissDisabled === false && busyUpdateState.dismissText === 'Download abbrechen' && busyUpdateState.dismissDanger === true && busyUpdateState.headerHidden === false);
     check('Update progress exposes an accessible live value', busyUpdateState.progressLabel === 'Update-Fortschritt' && busyUpdateState.progressText === 'Download 50%');
+    check('Update progress shows downloaded size, total size, speed, and ETA', busyUpdateState.progressDetails === '40.0 MB / 100.0 MB · 8.0 MB/s · ETA 00:08');
     check('Update download progress is green, wide, and places its status below the line', busyUpdateState.progressState === 'downloading' && busyUpdateState.progressColor === 'rgb(117, 211, 155)' && busyUpdateState.progressTrackWidth >= 390 && busyUpdateState.progressTextTop >= busyUpdateState.progressTrackBottom);
     check('Busy update preserves the available version subtitle while progress stays below the bar', busyUpdateState.messageHidden === false && busyUpdateState.messageText === 'Update v9.9.9 verfügbar');
 

tests/updater-version.test.js

@@ -103,6 +103,7 @@ test('buffered installer downloads yield between progress updates so the rendere
   let preparationFinished = false;
   let rendererObservedProgressBeforeFinish = false;
   let rendererObservationScheduled = false;
+  let nowMs = 0;
 
   try {
     await prepareUpdate(value => {
@@ -121,6 +122,7 @@ test('buffered installer downloads yield between progress updates so the rendere
         latestYmlUrl: 'https://update.invalid/latest.yml'
       },
       tempDir,
+      now: () => nowMs,
       fetchImpl: async url => url.endsWith('latest.yml')
         ? {
             ok: true,
@@ -132,9 +134,12 @@ test('buffered installer downloads yield between progress updates so the rendere
             status: 200,
             body: {
               getReader: () => ({
-                read: async () => readerIndex < chunks.length
-                  ? { done: false, value: chunks[readerIndex++] }
-                  : { done: true }
+                read: async () => {
+                  nowMs += 1000;
+                  return readerIndex < chunks.length
+                    ? { done: false, value: chunks[readerIndex++] }
+                    : { done: true };
+                }
               })
             }
           }
@@ -147,6 +152,10 @@ test('buffered installer downloads yield between progress updates so the rendere
       progress.filter(value => value.stage === 'downloading').map(value => value.percent),
       [25, 50, 75, 100]
     );
+    assert.deepEqual(
+      progress.filter(value => value.stage === 'downloading').map(value => [value.bytesPerSecond, value.etaSeconds]),
+      [[32768, 3], [32768, 2], [32768, 1], [32768, 0]]
+    );
   } finally {
     fs.rmSync(tempDir, { recursive: true, force: true });
   }