Add Midnight vortex animation and Ode to St Lucia

[tomadowley]

This PR adds a new interactive animation and a poetic Ode, and wires it into the existing canvas gallery.

What changed:

• README.md: Added an 'Ode to St Lucia' section celebrating the island.
• assets/animation-starfield-vortex.js: Implemented createStarfieldVortexProject, a Midnight vortex animation with starfield particles, parallax-like trails, and pointer-driven focus.
• assets/main.js: Imported the new animation and registered it in the projects list so it loads with the rest of the animations.

How it works:

• Seeds a set of stars with configurable colors, sizes, and motion.
• Renders a swirling vortex with motion and fading trails; pointer movement focuses the vortex.
• Designed to run with the existing canvas-based animation framework with no breaking changes.

How to test:

• Build or open the site and navigate to the animation gallery; hover or move the pointer over the canvas to see the Midnight vortex respond.