fix: rewrite hamburger menu using Alpine.js event dispatcher

fix: rewrite hamburger menu using Alpine.js event dispatcher

- Replace vanilla JS click handlers with Alpine.js @toggle-menu event
- Hamburger button dispatches toggle-menu event on click
- Menu overlay listens to toggle-menu and toggles menuOpen state
- Alpine controls visibility via :class bindings (opacity/invisible)
- Alpine controls panel slide via :class bindings (translate-x)
- All menu interactions (close button, links, ESC, backdrop) use Alpine
- Remove complex vanilla JS that wasn't working reliably
- Rebuild CSS: main.min.css updated

Co-Authored-By: Claude Haiku 4.5 <redacted>