Optimize Supertonic V3: Increase ONNX threads and tune default quality for local performance

Fix Supertonic V3: Remove legacy language tags causing distortion

Update Piper to 1.4.2 and Supertonic to V3

Fix: Grouped sentence chunks into visual paragraphs and improved TTS response speed

UI: Refined scrolling behavior and layout for better manual control

Fix: Stop audio instantly on paragraph change

Optimized server for concurrency and added full engine warmup

Integrated Supertonic-2 TTS and refined UI settings

fix: restore playback resume functionality

feat: keep current paragraph focused on typography changes

UI: Reset background for buttons using toc-item class

UI: Fixed sort menu unclickable on mobile by moving out of sticky header

UI: Fixed sort popover desktop placement

UI: Finalized mobile and desktop header and popover layouts

UI: Fixed book cover aspect ratio to 1:1.6 for mobile and web

Mobile: Standardize popover height and scrolling

Mobile: Finalize header alignment and popover bottom-sheets

Web: Remove settings scroll. Mobile: Fix header alignment and add drag handle.

Mobile: Increase bottom padding for settings and popovers

Mobile: iOS Safe Area support and absolute header alignment

Mobile: Fix header alignment and convert all popovers to bottom-sheets

Mobile: Perfect bottom-sheet placement for settings and add background overlay

Mobile: Fix reader touch dragging, consolidate CSS, and increase dock size

Mobile: Final fix for horizontal overflow and overscroll

Mobile UX: Disable horizontal scroll, make settings scrollable, and enlarge audio dock

Dynamic sleep timer colors based on user highlight selection

Final cleanup of Install App feature and redundant comments

Add sleep timer feature with countdown display and settings presets

Final polish for mobile header and audio dock style

Fix library back button styling for web

Fix reader header overlap and restore horizontal audio dock for mobile

Fix mobile header overlap and decode HTML entities in parser

Optimize Header and Audio Dock for mobile responsiveness

Safety First: Disable PWA SW and sanitize books mapping to fix black screen

Fix ReferenceError: Upload is not defined causing black screen

Fix syntax error and Vite build issues causing Vercel failure

Implement mobile-first responsive design with off-canvas sidebar

Cleanup: Remove test files, redundant scripts, and agent artifacts

Fresh start: optimized code for Vercel/HF with PWA and Speed Fixes