feat: optional YouTube Music source (cookies volume + wizard step)

Adds a step_youtube wizard prompt (enable + cookies host folder), the @YOUTUBE_VOLUME@ token in templates/compose/backend.yml substituted in compose_gen, a YOUTUBE_ENABLED/cookies env block, ensure_youtube_dir in lifecycle, en/ru strings, and a README step.

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

lib/compose_gen.sh

@@ -31,6 +31,13 @@ generate_compose() {
         webui_ports="    ports:${nl}      - \"\${WEBUI_PORT}:80\""
     fi
 
+    # YouTube cookies volume: mounted into api+worker only when the source is
+    # enabled. The host path comes from .env.deploy (YOUTUBE_COOKIES_HOST_PATH).
+    local youtube_volume=""
+    if [[ "$CFG_YOUTUBE" == "yes" ]]; then
+        youtube_volume="      - \${YOUTUBE_COOKIES_HOST_PATH}:/data/youtube"
+    fi
+
     # Caddy publish ports: 80/443 with a domain (auto-HTTPS), else plain HTTP.
     if [[ "$CFG_HTTPS" == "yes" ]]; then
         caddy_ports="      - \"80:80\"${nl}      - \"443:443\""
@@ -41,6 +48,7 @@ generate_compose() {
     # -- assemble ---------------------------------------------------------
     local backend webui caddy
     backend="$(_frag backend.yml)"
+    backend="${backend//@YOUTUBE_VOLUME@/$youtube_volume}"
     backend="${backend//@API_PORTS@/$api_ports}"
     backend="${backend//@API_DEPENDS@/$api_depends}"
     backend="${backend//@WORKER_DEPENDS@/$worker_depends}"

lib/env_gen.sh

@@ -93,5 +93,24 @@ generate_env() {
         } >>"$ENV_FILE"
     fi
 
+    # -- YouTube Music source ---------------------------------------------
+    # COOKIES_HOST_PATH is consumed by the compose volume; COOKIES_PATH is the
+    # in-container path the backend reads (only used when the file is present).
+    if [[ "${CFG_YOUTUBE:-no}" == "yes" ]]; then
+        {
+            echo ""
+            echo "# -- YouTube Music source -----------------------------------------------"
+            echo "YOUTUBE_ENABLED=true"
+            echo "YOUTUBE_COOKIES_HOST_PATH=${CFG_YOUTUBE_COOKIES_HOST_PATH}"
+            echo "YOUTUBE_COOKIES_PATH=/data/youtube/cookies.txt"
+        } >>"$ENV_FILE"
+    else
+        {
+            echo ""
+            echo "# -- YouTube Music source (disabled) ------------------------------------"
+            echo "YOUTUBE_ENABLED=false"
+        } >>"$ENV_FILE"
+    fi
+
     chmod 600 "$ENV_FILE"
 }

lib/lifecycle.sh

@@ -36,6 +36,17 @@ ensure_media_dir() {
     mkdir -p "$p"
 }
 
+ensure_youtube_dir() {
+    # YOUTUBE_COOKIES_HOST_PATH is only present when the YouTube source is
+    # enabled; create the folder so the bind mount has a real host directory
+    # (the user drops cookies.txt into it later).
+    local p
+    p="$(grep -E '^YOUTUBE_COOKIES_HOST_PATH=' "$ENV_FILE" | cut -d= -f2-)"
+    [[ -n "$p" ]] || return 0
+    [[ "$p" = /* ]] || p="${BOOTSTRAP_DIR}/${p#./}"
+    mkdir -p "$p"
+}
+
 lifecycle_pull() {
     ui_info "$(t pull_images "$(grep -E '^MCMA_IMAGE_TAG=' "$ENV_FILE" | cut -d= -f2-)")"
     ui_dim "$(t pull_hint)"
@@ -64,6 +75,7 @@ sys.exit(1)
 lifecycle_start() {
     local create_admin="${1:-no}"
     ensure_media_dir
+    ensure_youtube_dir
     lifecycle_pull
 
     local deps; deps="$(backing_services)"
@@ -111,7 +123,7 @@ lifecycle_update() {
     ui_ok "$(t done_title)"
 }
 
-lifecycle_up()     { ensure_media_dir; dc up -d; }
+lifecycle_up()     { ensure_media_dir; ensure_youtube_dir; dc up -d; }
 lifecycle_down()   { dc down; }
 lifecycle_logs()   { dc logs -f --tail=100; }