perf: parallel init with Promise.all, targeted DOM updates for download progress

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/renderer-queue.ts

@@ -179,6 +179,25 @@ async function createMergeGroupFromSelection(): Promise<void> {
     updateMergeGroupButton();
 }
 
+function updateQueueItemProgress(progress: DownloadProgress): void {
+    const items = byId('queueList').children;
+    const idx = queue.findIndex(i => i.id === progress.id);
+    if (idx < 0 || idx >= items.length) return;
+
+    const el = items[idx];
+    const bar = el.querySelector('.queue-progress-bar') as HTMLElement;
+    const text = el.querySelector('.queue-progress-text') as HTMLElement;
+    const meta = el.querySelector('.queue-meta') as HTMLElement;
+
+    if (bar) {
+        const pct = progress.progress > 0 ? Math.min(100, progress.progress) : 0;
+        bar.style.width = `${pct}%`;
+        bar.className = `queue-progress-bar${progress.progress <= 0 ? ' indeterminate' : ''}`;
+    }
+    if (text) text.textContent = getQueueProgressText(queue[idx]);
+    if (meta) meta.textContent = getQueueMetaText(queue[idx]);
+}
+
 function renderQueue(): void {
     if (!Array.isArray(queue)) {
         queue = [];

src/renderer.ts

@@ -5,14 +5,18 @@ const QUEUE_SYNC_HIDDEN_MS = 9000;
 const QUEUE_SYNC_RECENT_ACTIVITY_WINDOW_MS = 15000;
 
 async function init(): Promise<void> {
-    config = await window.api.getConfig();
+    const [loadedConfig, initialQueue, isDown, version] = await Promise.all([
+        window.api.getConfig(),
+        window.api.getQueue(),
+        window.api.isDownloading(),
+        window.api.getVersion()
+    ]);
+    config = loadedConfig;
     const language = setLanguage((config.language as string) || 'en');
     config.language = language;
-    const initialQueue = await window.api.getQueue();
     queue = Array.isArray(initialQueue) ? initialQueue : [];
-    downloading = await window.api.isDownloading();
+    downloading = isDown;
     markQueueActivity();
-    const version = await window.api.getVersion();
 
     byId('versionText').textContent = `v${version}`;
     byId('versionInfo').textContent = `Version: v${version}`;
@@ -66,7 +70,7 @@ async function init(): Promise<void> {
         item.downloadedBytes = progress.downloadedBytes;
         item.totalBytes = progress.totalBytes;
         item.progressStatus = progress.status;
-        renderQueue();
+        updateQueueItemProgress(progress);
         markQueueActivity();
     });