Release v0.19.0 — Session Prefetch, Scoped Permissions & Dark Theme Overhaul · OpenSource03/harnss

What's New

Session payload cache — prefetches up to 6 recent sessions via requestIdleCallback so switching is instant with no disk I/O
Metadata sidecar files — session listing reads tiny .meta.json files instead of parsing full multi-MB session files
Async session I/O — migrated all fs.existsSync/readFileSync calls to fs.promises.* for non-blocking session operations
Consolidated metadata sync — merged 4 separate setSessions(prev => prev.map(...)) effects into a single batched update
startTransition wrapping — session switch state updates are wrapped in React transitions for smoother UI

"Always allow" dropdown — split button on the permission prompt with per-destination scope (session, local project, shared project, user-global)
Permission rule forwarding — updatedPermissions flows through the SDK permission bridge so rules persist to the chosen settings file
Local settings source — all SDK query paths now include "local" in settingSources for .claude/settings.local.json support

Light glass tuning — separate gradient math for light glass mode with softer titlebar veils, adjusted shadow opacity curves, and color-mix(in oklab, white 97%, var(--background) 3%) surface color
Refined top scroll fade — lighter, shorter gradient (h-20/h-24), reduced radial shadow spread, and fine-tuned opacity breakpoints for both island and flat layouts
Transparency toggle — glass-enabled class now respects a harnss-transparency localStorage key, applied early in preload before React mounts
Darker window background — Electron window base color changed from #18181b to #040404 for true dark appearance
ShadCN Select component — new Radix-based <Select> replaces all native <select> elements in settings panels for consistent styling

Bash output truncation — long bash results (200+ lines) collapse with a "Show full output" toggle
Engine icons in sidebar — session items show per-engine/agent icons instead of generic message bubbles
AskUserQuestion redesign — tighter spacing, smaller type scale, and cleaner answer display
Icon picker fix — dropdown-to-popover transition uses onCloseAutoFocus prevention instead of fragile setTimeout
Message unqueue — new unqueueMessage action lets users remove queued messages before they're sent

getTopScrollProgress helper — extracted smoothstep scroll-progress calculation to a pure, tested function in chat-scroll.ts
Synchronous viewport sync — programmatic scrolls (jump-to-bottom, prepend anchor restore) now immediately update top-progress and scrolled-from-top state
useLayoutEffect for session reset — scroll position resets happen in layout phase to prevent flicker on session switch
Stale viewport ref guard — getViewport() checks isConnected to avoid operating on detached DOM nodes

Git status loading race — separate loadingRequestIdRef prevents stale requests from clearing the loading spinner
Switch request guard — switchRequestIdRef discards late-arriving disk loads when the user rapidly switches sessions
Non-blocking save on switch — saveCurrentSession() is now fire-and-forget (void) during session switches to avoid blocking the UI

Full Changelog: v0.18.1...v0.19.0