Milestone 1: Liquidsoap broadcasting skeleton

Liquidsoap (v2.4.5) container that plays the /cache directory in random
order and broadcasts it over HTTP at :8000/radio.mp3 (MP3 192 kbps).
mksafe guarantees a continuous stream (silence when the cache is empty).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

docker-compose.yml

@@ -0,0 +1,9 @@
+services:
+  stream:
+    build: ./stream
+    image: radieo-stream
+    ports:
+      - "8000:8000"          # flux HTTP : http://localhost:8000/radio.mp3
+    volumes:
+      - ./cache:/cache:ro    # jalon 1 : lecture seule, rempli à la main
+    restart: unless-stopped