Biomekka 1.8.33

Dashboard/Open Graph and storm lottery target update.

Changed:
- Added Open Graph/Twitter/canonical metadata to the ESP dashboard HTML for nicer link previews when biomekka.co.uk is shared.
- Storm lottery target is no longer fixed to 1.
- A fresh storm target roll is selected every time the paludarium becomes storm eligible after the dry/humidity arm period.
- Storm chance hit logic now triggers when the roll matches the current target.
- /status now exposes storm_target_roll for the dashboard.
- Dashboard storm dice text now displays the current target number instead of hard-coded target 1/Nat 1 wording.

Not changed:
- No pin, relay, Goblin command, sensor, MQTT topic, telemetry endpoint, lighting colour, storm duration, pre-storm, quiet mode, camera/proxy, YouTube, or Nginx changes.