Wire up container timezone via /etc/localtime bind mount

Container defaulted to UTC (no TZ configured), so calendar_run_time and
the scraper's date-of-week logic didn't match the user's local clock.
Uncomments the existing /etc/localtime mount and installs tzdata so the
host's zoneinfo symlink actually resolves instead of silently falling
back to UTC.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_013RbBoYm23muVyMZ18Ldqa6

docker-compose.yml

@@ -8,6 +8,6 @@ services:
       - "2323:2323"
     volumes:
       - ./data:/data
-      # Uncomment to share host timezone so RUN_TIME matches your local clock:
-      # - /etc/localtime:/etc/localtime:ro
+      # Shares host timezone so RUN_TIME matches your local clock:
+      - /etc/localtime:/etc/localtime:ro