Add reading progress bar, better empty states, and Edge TTS

UI Improvements:
- Reading progress bar at top of reader (tracks scroll position)
- Better empty state with illustration and helpful tips
- Edge TTS as default - fast streaming with Microsoft neural voices

TTS Options:
- Edge TTS (recommended): Fast, natural sounding, streams immediately
- Kokoro: High quality but slower (generates full audio first)
- Browser: Built-in fallback

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

docker-compose.yml

@@ -10,7 +10,15 @@ services:
     environment:
       - DATABASE_PATH=/app/data/readlater.db
 
-  # Kokoro TTS for high-quality text-to-speech
+  # Edge TTS - Fast streaming TTS using Microsoft's neural voices (recommended)
+  edge-tts:
+    image: travisvn/openai-edge-tts:latest
+    container_name: edge-tts
+    restart: unless-stopped
+    ports:
+      - "5050:5050"
+
+  # Kokoro TTS - High-quality but slower (generates full audio before playing)
   kokoro:
     image: ghcr.io/remsky/kokoro-fastapi-cpu:v0.2.1
     container_name: kokoro-tts