Allinea slate Cloud a AAC 48k mono e preferisce home in allocate.

Senza questo il telefono (mono 48k) veniva rifiutato sui nodi Hetzner e lo warm spare rubava le sessioni a home.

Co-authored-by: Cursor <cursoragent@cursor.com>

infra/stream-node/cloud-init.yaml

@@ -48,13 +48,12 @@ write_files:
       done
       docker pull bluenviron/mediamtx:latest
       docker rm -f mediamtx 2>/dev/null || true
-      # Slate offline (alwaysAvailable) — richiesta da Mediamtx::Client#create_path
-      # MediaMTX 1.20+: il publisher RTMP deve matchare canali audio della slate (stereo).
+      # Slate offline (alwaysAvailable) — richiesta da Mediamtx::Client#create_path.
+      # MediaMTX 1.20+: AAC del publisher RTMP deve matchare la slate.
+      # Allineato ad app Android (BroadcastConfig: 48 kHz mono) e infra/scripts/generate_slate.sh.
       mkdir -p /slates
-      if [ ! -f /slates/offline.mp4 ]; then
-        ffmpeg -y -f lavfi -i color=c=black:s=1280x720:d=2 -f lavfi -i anullsrc=r=44100:cl=stereo \
-          -c:v libx264 -t 2 -pix_fmt yuv420p -c:a aac -ac 2 -shortest /slates/offline.mp4
-      fi
+      ffmpeg -y -f lavfi -i color=c=black:s=1280x720:d=2 -f lavfi -i anullsrc=r=48000:cl=mono \
+        -c:v libx264 -t 2 -pix_fmt yuv420p -c:a aac -ac 1 -ar 48000 -shortest /slates/offline.mp4
       # Debian cloud image: docker.io senza apparmor_parser → serve unconfined o pkg apparmor
       docker run -d --name mediamtx --restart unless-stopped --network host \
         --security-opt apparmor=unconfined \