feat: enhance discovery, vibe sessions, and library enrichment

docker-compose.yml

@@ -57,7 +57,11 @@ services:
       - backend
 
   worker:
-    build: ./workers
+    build:
+      context: ./workers
+      # Keep the downloader absent unless an operator intentionally opts in.
+      args:
+        INSTALL_YTDLP: "false"
     restart: unless-stopped
     network_mode: host
     environment:
@@ -69,6 +73,13 @@ services:
       DISCOGS_TOKEN: ${DISCOGS_TOKEN}
       SOCKS_PROXY_URL: ${SOCKS_PROXY_URL}
       MUSIC_DIR: /music
+      # System E acquisition is intentionally disabled by default. To enable it
+      # an operator must build with INSTALL_YTDLP=true and set all three runtime
+      # gates below; no acquisition happens merely from graph discovery.
+      # MUZICK_ACQUISITION_ENABLED: "true"
+      # MUZICK_ACQUISITION_YTDLP_PATH: /usr/bin/yt-dlp
+      # MUZICK_ACQUISITION_ALLOWED_HOSTS: example.org
+      # MUZICK_ACQUISITION_DIR: .recommendations
       # Hard-deletion gates for the dislike lifecycle (invariant §C). All three
       # default to the safe value inside cleanup.service.ts; they are listed here
       # as documentation and are intentionally left unset.