fix(services): conditional caddy_net across all Docker service scripts

Only include the caddy_net network block in generated docker-compose.yml
files when ~/docker/caddy exists. Prevents "network caddy_net declared
as external, but could not be found" on standalone installs without Caddy.

Affected: actualbudget, archivebox, arm, audiobookshelf, calibre-web,
changedetection, drum-rhythm-game, emby, fmd, frigate, frigate-audio,
frigate-notify, gatus, homeassistant, immich, iopaint, jellyfin, joplin,
koha, lyrion, magicmirror, mail-archiver, mattermost, mealie, meshcentral,
n8n, nextcloud, ntfy, onlyoffice, portainer, stirling-pdf, syncthing,
traccar, unifi, uptimekuma, vaultwarden, wg-easy

Skipped: authelia (creates caddy_net itself), caddy, crowdsec, wolf,
wolf-pair, and services using network_mode: host with no caddy_net.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01D8ckUJQtj1pH8jtAddBDZs

services/frigate-audio.sh

@@ -375,6 +375,23 @@ ENVEOF
         [ -n "$DRI_LINE" ] && DEVICES_BLOCK="${DEVICES_BLOCK}\n      ${DRI_LINE}"
     fi
 
+    local _CADDY_NET_BLOCK=""
+    if [ -d "$DOCKER_DIR/caddy" ]; then
+        _CADDY_NET_BLOCK="    networks:
+      - caddy_net
+"
+    fi
+
+    local _CADDY_NET_SECTION=""
+    if [ -d "$DOCKER_DIR/caddy" ]; then
+        _CADDY_NET_SECTION="
+networks:
+  caddy_net:
+    external: true
+    name: ${SITE_CADDY_NET:-caddy_net}
+"
+    fi
+
     cat > "$DIR/docker-compose.yml" << 'COMPOSEEOF'
 # Frigate NVR + Mosquitto MQTT + frigate-notify
 # Generated by ubuntu-post-install setup.sh
@@ -416,9 +433,7 @@ COMPOSEEOF
       - "8554:8554"
       - "8555:8555/tcp"
       - "8555:8555/udp"
-    networks:
-      - caddy_net
-    healthcheck:
+${_CADDY_NET_BLOCK}    healthcheck:
       test: ["CMD", "curl", "-f", "http://127.0.0.1:5000/api/version"]
       interval: 10s
       timeout: 5s
@@ -451,10 +466,7 @@ COMPOSEEOF
     volumes:
       - ./frigate-notify/config.yml:/app/config.yml:ro
 
-networks:
-  caddy_net:
-    external: true
-    name: \${CADDY_NET:-caddy_net}
+${_CADDY_NET_SECTION}
 COMPOSEEOF
     log_success "docker-compose.yml written"