Add Nginx web server for browsing recordings

Serves the recordings directory over HTTP with autoindex on port 8080.
Users can browse by date and play MP3 files natively in the browser.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

docker-compose.yml

@@ -8,3 +8,13 @@ services:
     volumes:
       - ./rtl_airband.conf:/app/rtl_airband.conf:ro
       - /home/m/recordings:/recordings
+
+  web:
+    image: nginx:alpine
+    container_name: sdr-web
+    restart: unless-stopped
+    ports:
+      - "8080:80"
+    volumes:
+      - ./nginx.conf:/etc/nginx/conf.d/default.conf:ro
+      - /home/m/recordings:/recordings:ro