feat: initial implementation of Focus RSVP speed reader

- Pure frontend SPA (Vite + React 19 + TypeScript + Tailwind CSS v4)
- Spritz ORP engine with absolute center crosshair gaze fixation
- Multilingual hybrid segmentation via Intl.Segmenter with punctuation attachment
- Adaptive breathing rhythm delay algorithm for natural comprehension
- IndexedDB local bookshelf, progress persistence, and client-side EPUB/TXT/MD parsing
- Curated sci-fi, philosophy, and classic speech samples
- Dark/OLED/Sepia/Slate/Nord themes and rich keyboard controls

Co-Authored-By: Claude Code <noreply@anthropic.com>

vite.config.ts

@@ -0,0 +1,10 @@
+import tailwindcss from '@tailwindcss/vite'
+import react from '@vitejs/plugin-react'
+import { defineConfig } from 'vite'
+
+export default defineConfig({
+  plugins: [
+    react(),
+    tailwindcss(),
+  ],
+})