feat: add Ampache music streaming server to media stack

- Add ampache service to media/compose.yaml with PostgreSQL backend
- Create ampache database in postgres init script
- Configure Ampache environment variables in arty.yml
- Mount Music directory read-only
- Expose at ampache.media.pivoine.art via Traefik

core/postgres/init/01-init-databases.sh

@@ -45,6 +45,10 @@ psql -v ON_ERROR_STOP=1 --username "$POSTGRES_USER" --dbname "$POSTGRES_DB" <<-E
     SELECT 'CREATE DATABASE koel'
     WHERE NOT EXISTS (SELECT FROM pg_database WHERE datname = 'koel')\\gexec
 
+    -- Ampache music streaming database
+    SELECT 'CREATE DATABASE ampache'
+    WHERE NOT EXISTS (SELECT FROM pg_database WHERE datname = 'ampache')\\gexec
+
     -- Grant privileges to all databases
     GRANT ALL PRIVILEGES ON DATABASE directus TO $POSTGRES_USER;
     GRANT ALL PRIVILEGES ON DATABASE umami TO $POSTGRES_USER;
@@ -55,11 +59,12 @@ psql -v ON_ERROR_STOP=1 --username "$POSTGRES_USER" --dbname "$POSTGRES_DB" <<-E
     GRANT ALL PRIVILEGES ON DATABASE tandoor TO $POSTGRES_USER;
     GRANT ALL PRIVILEGES ON DATABASE asciinema TO $POSTGRES_USER;
     GRANT ALL PRIVILEGES ON DATABASE koel TO $POSTGRES_USER;
+    GRANT ALL PRIVILEGES ON DATABASE ampache TO $POSTGRES_USER;
 
     -- Log success
     SELECT 'Compose databases initialized:' AS status;
     SELECT datname FROM pg_database
-    WHERE datname IN ('directus', 'umami', 'n8n', 'linkwarden', 'joplin', 'mattermost', 'tandoor', 'asciinema', 'koel')
+    WHERE datname IN ('directus', 'umami', 'n8n', 'linkwarden', 'joplin', 'mattermost', 'tandoor', 'asciinema', 'koel', 'ampache')
     ORDER BY datname;
 EOSQL
 
@@ -77,4 +82,5 @@ echo "  • mattermost   - Chat platform database"
 echo "  • tandoor      - Recipe manager database"
 echo "  • asciinema    - Terminal recording server database"
 echo "  • koel         - Music streaming server database"
+echo "  • ampache      - Music streaming server database"
 echo ""