Add deployment reading windows and progress-aware quiz unlock

.env.example

@@ -9,4 +9,11 @@ SENTINEL_DATA_PATH=./data/sentinel
 SCRAPER_TOKEN_PATH=./.secrets/scraper_token
 TZ=Europe/Berlin
 COOKIE_SECURE=0
+# Optional server-enforced reading windows. Day keys: 0=Sunday through 6=Saturday.
+# Ranges may cross midnight. Multiple ranges per day are supported.
+# READING_WINDOWS_JSON='{"0":[["08:00","01:00"]],"1":[["07:00","24:00"]],"2":[["07:00","24:00"]],"3":[["07:00","24:00"]],"4":[["07:00","24:00"]],"5":[["07:00","24:00"]],"6":[["08:00","01:00"]]}'
+READING_TIMEZONE=Europe/Berlin
+READING_QUIZ_UNLOCK_MINUTES=60
+# Optional deployment-managed JSON file under DATA_PATH, e.g. /data/reading-quiz.json.
+# READING_QUIZ_CATALOG_PATH=/data/reading-quiz.json
 PROXY_NETWORK=mangacircus-edge