feat: startup performance — deferred analytics, lazy model revalidation, and flash-free window

- Show window only after ready-to-show to eliminate white flash on launch
- Fire-and-forget PostHog init to avoid blocking app.whenReady()
- Defer syncAnalyticsSettings to useEffect (after first paint, not before)
- Delay model cache revalidation by 3s to reduce startup IPC contention
- Add 50ms yield between sequential session prefetch loads
- Bump version to 0.20.0

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

Author: OpenSource03

electron/src/main.ts

@@ -71,6 +71,7 @@ function isMainRendererPermissionRequest(webContents: Electron.WebContents | nul
 
 function createWindow(): void {
   const windowOptions: Electron.BrowserWindowConstructorOptions = {
+    show: false,
     width: 1200,
     height: 800,
     // Matches the renderer's stricter island-layout minimum before first IPC sync,
@@ -109,6 +110,10 @@ function createWindow(): void {
 
   mainWindow = new BrowserWindow(windowOptions);
 
+  mainWindow.once("ready-to-show", () => {
+    mainWindow?.show();
+  });
+
   contextMenu({
     window: mainWindow,
     showSearchWithGoogle: false,
@@ -294,15 +299,17 @@ ipcMain.handle("speech:request-mic-permission", async () => {
   return { granted: true };
 });
 
-app.whenReady().then(async () => {
+app.whenReady().then(() => {
   // Migrate data from old "OpenACP UI" app directory before anything reads it
   migrateFromOpenAcpUi();
 
   createWindow();
   initAutoUpdater(getMainWindow);
 
-  // Initialize PostHog analytics (if enabled in settings)
-  await initPostHog();
+  // Initialize PostHog analytics (if enabled in settings) — fire-and-forget to avoid blocking startup
+  initPostHog().catch((err) => {
+    reportError("POSTHOG", err, { context: "startup-init" });
+  });
 
   // Allow microphone access for Whisper voice dictation (getUserMedia in renderer)
   session.defaultSession.setPermissionRequestHandler(

package.json

@@ -1,6 +1,6 @@
 {
   "name": "harnss",
-  "version": "0.19.1",
+  "version": "0.20.0",
   "productName": "Harnss",
   "description": "Harness your AI coding agents — one desktop app for Claude Code, Codex, and any ACP agent",
   "author": {

src/App.tsx

@@ -1,8 +1,14 @@
+import { useEffect } from "react";
 import { Toaster } from "sonner";
 import { TooltipProvider } from "@/components/ui/tooltip";
 import { AppLayout } from "@/components/AppLayout";
+import { syncAnalyticsSettings } from "@/lib/posthog";
 
 export function App() {
+  // Sync analytics opt-in state after mount — avoids blocking first paint with IPC calls
+  useEffect(() => {
+    syncAnalyticsSettings();
+  }, []);
   // Guard: if the preload script failed, window.claude won't exist.
   // Throwing here lets the ErrorBoundary show a visible message instead of a blank window.
   if (!window.claude) {

src/hooks/session/useSessionLifecycle.ts

@@ -222,19 +222,25 @@ export function useSessionLifecycle({
       }
     }).catch(() => { /* cache read is optional */ });
 
-    window.claude.modelsCacheRevalidate(preferredCwd ? { cwd: preferredCwd } : undefined).then((result) => {
-      if (cancelled) return;
-      if (result.models?.length) {
-        setCachedModels(result.models);
-        return;
-      }
-      if (result.error) {
-        toast.error("Failed to load Claude models", { description: result.error });
-      }
-    }).catch(() => { /* keep stale cache if revalidation fails */ });
+    // Defer revalidation (spawns a Claude SDK subprocess) to avoid competing with
+    // the startup IPC burst. The cached models from modelsCacheGet() above are
+    // sufficient for the initial render.
+    const revalidateTimer = setTimeout(() => {
+      window.claude.modelsCacheRevalidate(preferredCwd ? { cwd: preferredCwd } : undefined).then((result) => {
+        if (cancelled) return;
+        if (result.models?.length) {
+          setCachedModels(result.models);
+          return;
+        }
+        if (result.error) {
+          toast.error("Failed to load Claude models", { description: result.error });
+        }
+      }).catch(() => { /* keep stale cache if revalidation fails */ });
+    }, 3000);
 
     return () => {
       cancelled = true;
+      clearTimeout(revalidateTimer);
     };
   }, [getProjectCwd]);
 
@@ -284,17 +290,19 @@ export function useSessionLifecycle({
         } finally {
           inFlightPrefetchRef.current.delete(session.id);
         }
+        // Yield between sequential loads to let the main process event loop breathe
+        await new Promise((r) => setTimeout(r, 50));
       }
     };
 
     if (typeof window.requestIdleCallback === "function") {
       idleId = window.requestIdleCallback(() => {
         void run();
-      }, { timeout: 1500 });
+      }, { timeout: 5000 });
     } else {
       timerId = setTimeout(() => {
         void run();
-      }, 250);
+      }, 3000);
     }
 
     return () => {

src/main.tsx

@@ -3,7 +3,7 @@ import { createRoot } from "react-dom/client";
 import { PostHogProvider } from "@posthog/react";
 import { ErrorBoundary } from "./components/ErrorBoundary";
 import { migrateLocalStorage } from "./lib/local-storage-migration";
-import { initPostHog, syncAnalyticsSettings, posthog } from "./lib/posthog";
+import { initPostHog, posthog } from "./lib/posthog";
 import { App } from "./App";
 import "./index.css";
 
@@ -13,8 +13,8 @@ migrateLocalStorage();
 // Initialize posthog-js (starts opted-out until settings confirm opt-in)
 initPostHog();
 
-// Sync analytics opt-in state from main process settings once available
-syncAnalyticsSettings();
+// Analytics opt-in sync is deferred to after React mount (in App.tsx useEffect)
+// to avoid firing IPC calls before first paint.
 
 createRoot(document.getElementById("root")!).render(
   <StrictMode>