Dashboard UI Polish / Mobile Responsive Upgrade

Changed:
- Reorganized scoreboard dashboard into clean Live Hero, Preview, Runs, Extras, Wickets, Match Setup, Live Tools, Next Innings, End/Reset sections.
- Mobile-first responsive layout with horizontal top navigation and sticky control tabs.
- Larger run buttons for easy touch operation on mobile.
- Extras and wickets remain connected to the smart scoring modal logic.
- Existing scoring functions/API calls are unchanged.
- Overlay design and animation logic are unchanged.

Updated files:
- partials/scoreboard_panel.php
- assets/css/dashboard.css
- assets/js/core.js