Discovery harvest routes, nightly schedule and per-user refresh (BL-0051)

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docker-compose.yml

@@ -58,6 +58,8 @@ services:
       READING_QUIZ_CATALOG_PATH: ${READING_QUIZ_CATALOG_PATH:-}
       SCRAPER_URL: http://scraper:8091
       SCRAPER_TOKEN_FILE: /run/secrets/scraper_token
+      DISCOVERY_HARVEST_AT: ${DISCOVERY_HARVEST_AT:-03:30}
+      DISCOVERY_ANILIST_URL: ${DISCOVERY_ANILIST_URL:-}
     networks: [backend, egress]
     healthcheck:
       test: [CMD, node, tools/healthcheck.js, reader]