Fix build: generate settings.json from env vars at runtime

settings.json is gitignored (contains token). entrypoint.sh writes it
from OUTLINE_URL / OUTLINE_TOKEN env vars on container start.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

docker-compose.yml

@@ -5,6 +5,9 @@ services:
     restart: unless-stopped
     networks:
       - domnet
+    environment:
+      - OUTLINE_URL=${OUTLINE_URL:-http://outline:3000}
+      - OUTLINE_TOKEN=${OUTLINE_TOKEN}
     ports:
       - "8181:8080"
     labels: